From: Roger Baker Subject: Re: VBB Feedback Date: Wed, 31 Dec 1997 14:43:22 -0600 Friends, There has been a lot of good discussion of force balancing feedback lately, an approach which is pretty much needed for vertical instruments and likely could be used with advantage the Lehman configuration too. Let me add a few comments of my own based on practical experientation. I remain in awe of the experts on such matters. One way to use force feedback, appropriate when the feedback force must be weak, is simply to use a very low pass filter to apply a little trimming force to recenter the DC displacement sensor in its most sensitive zone. This is perhaps best described as drift compensation and sacrifices very low frequency response by constantly nudging the sensor in the direction of its slow average midpoint reading. The signal used is the relatively fast response from the sensor, which may still be noisy due to natural period oscillations. A practical example from my recent experience is a torsion magnetometer which uses a Helmholtz coil to apply a weak field to keep a light beam centered in the detector. The fast oscillations of the magnet/mirror still needed to be damped magnetically with a copper ring. This method is very easy to apply and is intuitive and straightforward and nothing much can go wrong but it doesn't achieve tight dynamic control over the feedback loop. Tight feedback loops and servosystems with response times shorter than the natural period of the system are the best way to go, but tend to require complex analysis to achieve optimum results. Horowitz and Hill deal with the elements of stability criteria in the Art of Electronics. PHDs and mathematicians are in high demand where control system design involving nested feedback loops is concerned. There are some standard tricks that can be used to partly tame control systems and allow maximum gain in the feedback loop without oscillation such as a notch filter to kill gain at the natural period of the system, linking the sensor as closely as possible to the source of force, reducing feedback gain until the system stabilizes, etc. I have found it possible to use a simple adjustable filter in the feedback loop between the voltage output from the sensor and the force coil to stabilize several different magnetic force feedback systems. Assume we have a twelve volt regulated power supply with a virtual ground, a reference point at the voltage midpoint. Our displacement sensor generates a DC voltage which fluctuates above and below this ground reference and we want to feed back magnetic force to push a suspended mass very nearly back towards the point that results in the sensor output being the same as the ground reference voltage, plus six volts in this case. We can feed back the difference betwen the sensor output and the reference voltage straight into a magnetic coil which has one lead tied to this midpoint reference so that the force will try to push the system back to the midpoint. Which is when the system will usually turn into an oscillator, and which we don't want, but it usually means we're on the right track. Instead, I tie the noninverting input of an op amp to the reference voltage. Then I use about a one meg potentiometer and about a one MFD capacitor connected together in parallel between the buffered (meaning we run it through a little op amp voltage follower to beef up its output current a little) sensor output and the inverting input of the op amp. Then I put a second identical pot/cap pair in parallel between the inverting input of the op amp and its output. This is where the feedback resistor of the op amp normally goes. Thats it. The fact is that in many cases some empirical setting of the two pots will OFTEN kill the feedback oscillations and cause the system to lock onto and control the position of the mass in the desired and stable fashion. I like to follow the sensor voltage with a DC amplification stage, where the voltage signal is increased by ten or a hundred times and the output fed into an LED so that one can see the system stabilize by the lack of flickering at the natural oscillation period of the system. This amplified DC output from the sensor is also used as the data stream. The practical effect of such a filter is consistant with all the recent discussion, but I offer it here as a practical way to tame feedback oscillations in systems with natural periods of less than a second. Since magnetic coils tend to have a low resistance, we may need to hang a booster transistor between the output of the op amp and the coil to give lots of current to handle peak demand, but normally the system will probably be nearly balanced and the power demand on the force coil will be low. --Yours, Roger Baker At 09:39 PM 12/30/97 -0600, you wrote: >Karl and co, >Karl, >Our mail passes in the dark, or wherever internet mail goes. I just sent >you: (in case you didn't get it.): > >Karl, >I think I told you already that I have have made a pass at a transfer >function for a 40 second To for your instrument with these >parameters: r = 212 800 V/M (requires 20x gain after your LVDT), Gn = >5.1N/A (for your main coil), M = 0.3kg (much reduced from your 2.27kg, or 5lb, >but needed for the flatness to 10 hz, with damping at 0.69), C= 16 uf, >Rp = 361K ohms, RI = 127K, Rf = 7 ohms, TI = 20 seconds, and To = >4 seconds. This gives a response of 3685 volts/m/sec, flat from 40 >seconds to 10 hz. >Maybe these will be helpful for your new vertical. > >I wasn't sure if I sent all the numbers before. > >Regarding your analysis of the VBB feedback, it is pretty good on most points. >I tend to rely on the mathematical model as strongly as the engineering >intuition to understand what is going on. > >As I have mentioned before, the feedback is still a summation of currents >into the force coil, NOT voltages. So inserting a voltage amplifier between >the feedback elements and the coil will not produce a VBB response. Maybe >a "Norton" current amp might work, but unless the differential and integral >currents can both be controlled by their circuit elements, their effect >will be nil. In the transfer function, the flat response occurs when the >differential feedback dominates at less than To with the same magnitude that >the integral feedback dominates below To. In fact, this creates an oscillator >right AT To, so the proportional current through Rp is needed to damp the >system, which will actually oscillate if Rp is open. > >Regarding the relative DC or static mass movement (as compared with >the dynamic movement, which is much less): it is controlled by both the >proportional and integral currents, and depends on the sensitivity >of the mechanical suspension restoring force, which ideally would be >zero and the period infinite. However, in a stable instrument it is handy >to have the mass come to an equilibrium position, which is even more useful >since the restoring force also aids in dealing with significant >temperature effects. So the mechanical restoring force is finite but small, >meaning that the feedback will allow some DC movement of the mass. > >This amount is easily determined by measuring the displacement output >with the feedback on as well as off. On the prototype here, the ratio >is about 10 to 1. This also means that if I determine the sensitivity of >my 5-turn calibration coil (using the VRDT with the feedback off) to be >25 nanometers / microamp (it is actually 26.4), the mass only moves >2.5 nm /uamp. I need a step current of 30ua to produce a voltage of about >100 mv (peak pulse voltage) at the VBB output, which is equilavent to an >actual step movement of the mass of 12 nanometers. Naturally, if the >feedback perfectly controlled the static position of the mass, a step >calibration would not work except for the transient time of Td. > >Regarding the sensitivity of the displacement transducer: with a sensitivity >of say 50mv/micron and a 10x amp, it is 0.5 Volt/micron, or 500V/mm, or >500 000 Volts/meter. Sounds like a lot, until you realize that we are >trying to measure 10**-10 meter, or 0.1 nanometer, which would have a >voltage of only 5 microvolts, which is near the low noise limit of even >high quality amplifiers. With my prototype here, the VBB output is about >3200 V/M/sec, but the 6-second microseisms come in at only 1 to 5 millivolts. >And it took the M 7.7 in Tibet to clip the 12-bit digitizer here at 200mv. >My maximum output is 7 volts, so I need the 16-bit ADC; actually, if my >noise floor IS 5 microvolts, I have a dynamic range of 122.9db, which would >take a 20-bit ADC to resolve. And conversely, a peak of 7 volts is a peak >velocity of 2.18mm/second, or a pretty good shake (you can feel 10 microns/ >second). > >In terms of earthquake magnitude, if we have a Mb3.0 at 110km (1 deg), and >Mblg = 3.75 + 0.9*log[DELTA](degrees) +log[A](microns), the amplitude is >0.178 microns (at 1 hz). A magnitude 5 at the same distance would have an >amplitude of 17.8 microns. > >And finally, regarding the size of the mass: larger is better if you have >a powerful feedback coil, like the 90N/A in the S5000 with the ll kg >mass, but the commercial VBB sensors have masses from 0.3 to 0.6 kg, with >force coils around 20N/A for more high frequency output. If I model your >sensor with the 2.7kg mass, the response is a rounded bump, much like a >narrowband LP seis; the feedback currents simply cannot control it. >The response is nicely broad and flat with the 0.3kg mass. > >I hope that I have answered your questions. > >Regards, >Sean-Thomas > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Marnie Gannon Subject: Yikes..Mammoth again Date: Wed, 31 Dec 1997 13:55:09 -0700 Update time = Wed Dec 31 12:47:29 PST 1997 Here are the 30 most recent earthquakes and all big earthquakes on this map... MAG DATE LOCAL-TIME LAT LON DEPTH LOCATION y/m/d h:m:s deg deg km 1.7 97/12/31 12:44:36 37.64N 118.87W 7.2 6 mi E of MAMMOTH LAKES 1.4 97/12/31 12:43:36 37.63N 118.84W 7.5 7 mi E of MAMMOTH LAKES 1.9 97/12/31 12:43:03 37.63N 118.86W 7.7 6 mi ESE of MAMMOTH LAKES 3.2 97/12/31 12:41:47 37.63N 118.86W 7.0 6 mi E of MAMMOTH LAKES 1.4 97/12/31 12:41:28 37.63N 118.83W 8.5 8 mi ESE of MAMMOTH LAKES 3.7 97/12/31 12:39:52 37.62N 118.86W 5.2 6 mi ESE of MAMMOTH LAKES 4.7 97/12/31 12:36:47 37.63N 118.87W 6.9 6 mi ESE of MAMMOTH LAKES 1.8 97/12/31 12:36:31 37.63N 118.87W 6.3 6 mi E of MAMMOTH LAKES _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Karl Cunningham Subject: Re: VBB Feedback Date: Wed, 31 Dec 1997 13:29:38 -0800 Sean-Thomas: To increase the effective feedback coil sensitivity, consider a current-in/current-out amplifier. I haven't looked into the magnitude of noise and drift introduced from the op-amp, but the following circuit may work: R1 +---\/\/\/\-----+ | | | |\ | | | \ | Current from VBB Feedback Ckt ---+---|- \ | R2 | >-----+---\/\/\/\---- To Feedback coil +---|+ / | | / | |/ -+- \ / V The current gain is R1/(R2+Rf), where Rf is the feedback coil's dc resistance. R2 should be substantially larger than the inductive reactance of the feedback coil at the highest frequency of significant energy from the VBB feedback. Otherwise, the drive to the coil is not so purely a current and, as you say, the result won't be a true VBB response. For speaker coils and the like, this shouldn't present a problem. Also to be considered is the emf generated across the coil when moving in the magnetic field, which will disrupt the true current feedback. So long as this emf is low compared to the voltage across (R2+Rf) at the same point in time, this shouldn't be a problem either. Your sensitivity/dynamic range numbers sound good. I've done a spreadsheet with your equations so I can play with the numbers and look at the results. I'll see if I can come up with a solution with viable component values for my vertical. Thanks a lot for your help. Karl Cunningham La Mesa, CA. PSN station #40 karlc@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: TESMECO Subject: great post Date: Wed, 31 Dec 1997 17:11:19 EST we should send more info like this on this list thanks greatly appreciated TIM SLU SEEYA _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Bob Fryer Subject: Re: great post Date: Wed, 31 Dec 1997 14:45:02 -0800 Uhhh, Tim, What post were you referring to? Bob F >we should send more info like this on this list > > thanks greatly appreciated TIM SLU > > >SEEYA > >_____________________________________________________________________ > ----- earthquake WARNING research ----- --- animals, people, scientific evidence --- --- http://www.teleport.com/~bfryer --- _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: TESMECO Subject: Re: great post Date: Wed, 31 Dec 1997 18:04:32 EST the mammoth info great visual aid it was all compiled so ididnt have to go get thats all tim slu seeya _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: fmurray@......... (frank murray) Subject: Re: Notice the 3 SAF M3's... Date: Wed, 31 Dec 1997 23:12:59 GMT On Wed, 31 Dec 97 19:40:20 +0000, frank condon wrote: >Bombay Beach lives for another day! After getting out the maps and = locating the >faults in relation to the most recent activity, I believe your statement= is=20 >correct. Isn't it kind of close to the cinder cones at Obsidian Butte? = Could=20 >we be looking at the start of another geothermally active spot like = Mammoth=20 >Lakes and Little Lake? coincidentally, or perhaps not, when the niland quake at 14:32:03 occurred, the sequence at mammoth slowed to a thirteen minute gap between quakes...no other gap at mammoth had exceeded about three minutes since the M4.8...nor had any other niland quakes occurred during the time since that M4.8...after that thirteen minute gap the quakes at mammoth returned to a frequency of about one per minute...speculation??... frank fmurray@......... for my electronic college proposal see: http://home.att.net/~fjtmurray/ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: Re: VBB Feedback Date: Wed, 31 Dec 1997 17:57:33 -0600 (CST) Karl, Of course the only thing to do is to try it. My feeling is that if the designers of the commercial instruments don't do it, it probably won't work. I believe that the reason is, as I have mentioned before, that the feedback currents MUST be controlled by the three feedback elements Rp, C, and RI sumultaneously controlling the current through the feedback coil. Anything between them and the coil modifies their behavior, and the transfer function, which is actually an expression of accelerations, doesn't work. I know that your present coil will work as is; if not, speakers are cheap. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: STM-8 photos Date: Wed, 31 Dec 1997 18:05:16 -0600 (CST) To those interested in the broadband leaf spring vertical seismometer: I have spent my holiday getting up to speed with a web page at //www.eas.slu.edu/People/Staff/STMorrissey. It is a bit primitive so far, and the paper on the homemade seis is in limbo until I can find a converter from RTF to .html, but I have posted a few photos of the leaf-spring prototype. Your comments and suggestions are appreciated. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Stephen Caruso Subject: digression? Date: Wed, 31 Dec 1997 20:19:00 -0500 (EST) I was wondering if anyone has an update on the meteor impact in greenland? STEPHEN CARUSO CET KB8UGH "Coincidence is a shortsighted mental delusion" _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: frankcnd@.......... (Frank Condon) Subject: Re: Yikes..Mammoth again Date: Wed, 31 Dec 1997 17:45:42 -0800 (PST) So Mammoth Mountain takes a vacation for the holidays. But, returns to celebrate the New Year with a bang! Frank Condon mail to:frankcnd@.......... "Located in the seismic corridor somewhere between Fontana & Mammoth Lakes" >Update time = Wed Dec 31 12:47:29 PST 1997 >Here are the 30 most recent earthquakes and all big earthquakes on this >map... > >MAG DATE LOCAL-TIME LAT LON DEPTH LOCATION > y/m/d h:m:s deg deg km > >1.7 97/12/31 12:44:36 37.64N 118.87W 7.2 6 mi E of MAMMOTH LAKES >1.4 97/12/31 12:43:36 37.63N 118.84W 7.5 7 mi E of MAMMOTH LAKES >1.9 97/12/31 12:43:03 37.63N 118.86W 7.7 6 mi ESE of MAMMOTH LAKES >3.2 97/12/31 12:41:47 37.63N 118.86W 7.0 6 mi E of MAMMOTH LAKES >1.4 97/12/31 12:41:28 37.63N 118.83W 8.5 8 mi ESE of MAMMOTH LAKES >3.7 97/12/31 12:39:52 37.62N 118.86W 5.2 6 mi ESE of MAMMOTH LAKES >4.7 97/12/31 12:36:47 37.63N 118.87W 6.9 6 mi ESE of MAMMOTH LAKES >1.8 97/12/31 12:36:31 37.63N 118.87W 6.3 6 mi E of MAMMOTH LAKES > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: dean sevold Subject: Fwd: Re: Meteorite fall Date: Wed, 31 Dec 97 18:58:00 PST Date: Tue, 30 Dec 97 11:41:48 PST From: Klaus Georg Hansen To: dean sevold Subject: Re: Meteorite fall Dear Dean No news - Nothing will happen before January 2nd 1998. I'll keep you informed. Happy New Year. Klaus This is all the news from greenland, but am expecting more shortly Deasn _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Ken Navarre Subject: Re: LEAF-SPRING Date: Wed, 31 Dec 1997 19:22:32 -0800 (PST) On Mon, 29 Dec 1997, S-T Morrissey wrote: > Ken and Jim, > The word to the wise about out-of-control leaf springs IS good advice. > One of mine got loose and flung a good collection of small stainless > hardware into the next room, causing my dogs to panic and hide in the > bedroom. Yeah, that sounds like what I observed... :( [snip] > Regarding damping with magnets, it was used on all the early seismometers > that has optical levers. It uses the principle of eddy currents, where > a thick copper vane moves in a very strong magnetic field. The movement > causes currents in the copper, whose induced field counters the motion. > I would consider using rare-earth magnets with an old real copper penny. I've installed the magnet from a large speaker in the vertical plane under the end of the boom. For damping I've hung a piece of copper salvaged from a high voltage electrical bus its 4" x 4" x 1/4" and weighs a couple pounds. A 2 mm seperation between the magnet and copper damps the swing in 2 cycles. A small ceramic magnet is attached to the top of the boom and faces the sensing coil. The sensing coil is mounted with aluminium angle and is easily adjusted to minimal spacing. This arrangement is certainly no improvement to Sean's design but it gave me a vertical to get on-line while I get up to speed with the electronics. KEn _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: New Event Date: Wed, 31 Dec 1997 12:16:39 -0800 Hi all Has anyone picked up a fairly large distant event @ about 06:10:51 UTC 01/01/98? It's possible I'm picking up wind vibrations. Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: frankcnd@.......... (Frank Condon) Subject: Re: New Event Date: Thu, 1 Jan 1998 00:57:10 -0800 (PST) I see this one is listed for the proper time. 98/01/01 06:11:16 24.00N 141.99E 33.0 6.7Mb B VOLCANO ISLANDS REGION Must not be the wind. Frank Condon >Hi all > Has anyone picked up a fairly large distant event @ about 06:10:51 >UTC 01/01/98? It's possible I'm picking up wind vibrations. > Barry > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Seisguy Subject: Fwd: Earthquakes Fewer, Deadlier in '97 Date: Thu, 1 Jan 1998 07:50:58 EST 
Earthquakes Fewer, Deadlier in '97


.c The Associated
Press


 WASHINGTON (AP) - The U.S. Geological Survey reports there were fewer
earthquakes than usual in 1997, but they killed more people.

The agency said Wednesday it recorded 17 major tremors during the year,
meaning those with a magnitude of 7.0 or more and thus capable of widespread,
heavy damage.

The annual average is 20 major quakes. There were 21 in 1996.

Meanwhile, the agency said it recorded the first significant quake of 1998 at
1:11 a.m. EST today in a string of unoccupied volcanic islands off Japan.

It said the epicenter of the quake, which recorded a preliminary magnitude of
6.5, was about 65 miles southwest of Iwo Jima and was unlikely to have been
felt because of the isolated location in the Pacific Ocean. There were no
reports of damage.

Despite the decline in temblors, the 1997 death toll was at least 2,913, up
from 449 in 1996, according to figures compiled by the Survey's National
Earthquake Information Center in Golden, Colo.

The year's deadliest earthquake struck northern Iran on May 10 with a
magnitude of 7.1. It caused at least 1,567 deaths, 2,300 injuries and left
50,000 homeless.

In the United States the year's strongest quake had a magnitude of 4.9 and
struck the state of Washington in June, causing slight damage at Bremerton and
Poulsbo.

Other significant earthquakes for the year occurred near the East coast of
Kamchatka, Russia, and near the coast of central Chile.

The strongest earthquake in the world in 1997 struck Xizang Province, Tibet,
about 520 miles north-northeast of Katmandu, Nepal, on Nov. 8.

AP-NY-01-01-98 0701EST


 Copyright 1997 The Associated
Press.  The information  contained in the AP news report may not be published,
broadcast, rewritten or otherwise distributed without  prior written authority
of The Associated Press. 


 

To edit your profile, go to keyword NewsProfiles.
For all of today's news, go to keyword News.
From: Robert L Barns <75612.2635@..............> Subject: Rockland filter Date: Thu, 1 Jan 1998 09:16:44 -0500 Hi gang, Here's something you might look for at a hamfest or on used equipment lists. I find it a very useful accessory to my Lehman. I got it from Bi= ll Scolnic. He found it at a hamfest. He uses a Kron-Hite filter which I think is quite similar. I'm guessing that $100 or so might get one or th= e other at a hamfest. It is a Rockland Systems Corp. adjustable filter, Model 1022F. It is i= n a 19" rack mount case 5 1/2" high and is not very heavy. It contains 2 identical sections and the data below are for each section. I don't have the manual so the data are my measurements. A switch selects either low or high pass. There are 3 decimal dials (X.XX) and a 1X, 10X, 100X and 1000X range switch. This allows setting the knee frequency from 0.01Hz to 9,990 Hz! A switch selects either 0 or 20db gai= n. With the knee frequency set at either 0.08Hz or 200Hz, I found that the slope above the knee of the low pass filter is 24db/octave with no vis. ripple. Who could ask for anything more? The output is from DC with an offset in the output of about 5 mV and I saw no clipping with output voltages up to 9V. The input impedence is 1= megohm. There is a switch for each section labelled BW-AC. Can anyone explain this switch? I don't know the vintage but found it interesting that the active components look to be all transistors-no op-amps. When I got it, the lef= t section worked fine but the right section was a mess. Each section consists of 5 or 6 small (3X4" about) plug-in cards. I started to troubleshoot the right section by swapping these cards from section to section but I discovered that one of the cards in the right section was plugged-in BACKWARDS. Putting this in the right way fixed it. Since I have only one seismometer, I'm using it set at 0.08Hz with the= two sections in series so that the slope above the knee is 48db/octave. = With my old home-made 6-pole 0.08Hz filter, I could always see some of th= e noise peak at 0.016Hz. With 48 db/octave, this peak is not seen. A filter which is so easily adjusted opens the door to various experiments. Happy hunting & Happy New Year! Bob Barns = = _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Bob Thomasson <102073.3346@..............> Subject: Re: Notice the 3 SAF M3's... Date: Thu, 1 Jan 1998 12:58:56 -0500 <> The same day of the Sylmar, CA quake in 1970 a new fumarole opened up at Hot Creek near Mammoth. The USGS claimed it was pure coincidence, but it= does make you wonder, doesn't it? Regards, Bob _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Norman Davis WB6SHI Subject: Re: STM-8 photos Date: Thu, 01 Jan 1998 11:48:22 >I have spent my holiday getting up to speed with a web page >at //www.eas.slu.edu/People/Staff/STMorrissey. Just tried it and it says no such page Norman Davis WB6SHI Email normd@............. Shingle Springs, Ca, USA it ain't local... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: RADIOTEL Subject: SEAN-THOMAS'S WEB PAGE Date: Thu, 1 Jan 1998 14:39:57 EST TO: SEAN-THOMAS I think I may have copied your web page address incorrectly. Tried to access it but was informed repeatedly that AOL could no find URL. Can you give it again. I copied: http://www.eas.slu.edu/People/Staff/STMorrissey Jim Allen Cerritos, California _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jim Hannon Subject: Re: STM-8 photos Date: Thu, 01 Jan 1998 13:54:19 -0600 Norman Davis WB6SHI wrote: > > >I have spent my holiday getting up to speed with a web page > >at //www.eas.slu.edu/People/Staff/STMorrissey. > > Just tried it and it says no such page > > Norman Davis WB6SHI > Email normd@............. > Shingle Springs, Ca, USA it ain't local... > I had to fiddle around a little to find it. TRY http://www.eas.slu.edu/People/STMorrissey/index.html -- Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N 91,39.26W WB0TXL _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Charlie Rond Subject: Re: SEAN-THOMAS'S WEB PAGE Date: Thu, 01 Jan 1998 15:16:40 -0600 Jim, >TO: SEAN-THOMAS > >I think I may have copied your web page address incorrectly. Tried to access >it but was informed repeatedly that AOL could no find URL. Can you give it >again. I copied: http://www.eas.slu.edu/People/Staff/STMorrissey >Jim Allen >Cerritos, California My apologies to Sean-Thomas for speaking for him, but I've located his page. http://www.eas.slu.edu/People/STMorrissey/index.html Thought I might step in for him while he's watching the football games :-) Happy New Year! Charlie Rond -\/\--Public Seismic Network-Memphis rond@................ (901) 360-0302 [ free BBS ] http://gandlf.ceri.memphis.edu/~rond http://gandlf.ceri.memphis.edu/~rond/psn _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: frankcnd@.......... (Frank Condon) Subject: Current Status of Mammoth Date: Thu, 1 Jan 1998 13:37:29 -0800 (PST) Hi All: Finally they updated the Web page that is dedicated to telling the public about the CURRENT CONDITION at Mammoth Lakes: --------------------------------------------------------------------------- Caldera activity: An energetic swarm of earthquakes in the south moat of the caldera (centered in the vicinity of the airport, 6 to 7 miles ESE of Mammoth Lakes) began with a M=4.8 earthquake at 12:37 PM on December 31. This swarm has included nearly 1,000 events through 9:45 AM on the 1st as detected and located by the realtime computer system. Some 48 of these earthquakes have magnitudes of M=2.5 or greater and 13 have magnitudes of M=3.0 or greater. Swarm earthquakes with magnitudes of M=3.5 or greater include M=3.6 and M=3.7 events at 12:40 PM, a pair of M=3.5 events at 4:55 PM and 9:32 PM all on the 31st, and a M=3.8 event at 4:19 AM on the 1st. The latter was part of a second swarm centered 2 miles ESE of Mammoth Lakes that began at 4:15 AM on the 1st. The pattern of ground deformation has not shown any marked changes associated with this swarm activity. The resurgent dome continues to inflate at about the same rate as observed in late-October and early November. The condition remains GREEN. ----------------------------------------------------------------- A strong upsurge in activity around the full Moon... Hmm! Is there a corelation between volcanic activity and the phases of the Moon? Could it be the ocean tides have an effect, too! Frank Condon mail to:frankcnd@.......... "Located in the seismic corridor somewhere between Fontana & Mammoth Lakes" _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: RADIOTEL Subject: Re: SEAN-THOMAS'S WEB PAGE Date: Thu, 1 Jan 1998 17:58:40 EST TO: CHARLIE ROND Thanks Charlie. Sean-Thomas's web page is very nice. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "David A. Nelson" Subject: Re: Current Status of Mammoth Date: Fri, 02 Jan 1998 12:03:26 +1200 >A strong upsurge in activity around the full Moon... Hmm! Is there a >corelation between volcanic activity and the phases of the Moon? Could it be >the ocean tides have an effect, too! > the 30 dec new moon not full moon but but sun and moon wouls be pulling in same direction Dave Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson ZL4TBN 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: RADIOTEL Subject: EMON CONFIGURATION Date: Thu, 1 Jan 1998 19:51:13 EST TO: BOB HAMMOND AND ALL LIST MEMBERS Thanks to the assistance of Bob Hammon I now have EMON up and running. I have several questions: 1. Is there a way to change the resolution? My screen shows a signal pattern with the dots Not Connected. I have changed the verticle compression of displayed signal to 20 and the horizonal to 15 which seemed to help somewhat. 2. Is there a way to add color to the screen, even IBM Blue? When the program saves the traces and I view it in Winquake the trace is good. I am using EMON configured for the CIO-DAS08/Jr 12-bit A/D. Any suggestions would be appreciated. Jim Allen Cerritos, California _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jim Hannon Subject: 3d map visulation Date: Thu, 01 Jan 1998 18:59:05 -0600 A friend just sent me this link. Very interesting freeware for visulation of 3d map data and some links to online 3d map data. Haven't tried it out yet. http://www.monumental.com/rshorne/3dem.html -- Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N 91,39.26W WB0TXL _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: web page Date: Thu, 1 Jan 1998 19:06:46 -0600 (CST) Hi Meredith, Norman,Jim, Larry, Charlie. Mike, et al. I appreciate your comments on my effort at a web page. Sorry about making it hard to find; when I start netscape on our server, it defaults to the department page, and I just click on the People, Staff. etc to get around. I guess other access needs the final path links. I appreciate Charlie's effort at solving the problem. I wonder what an aol access would find at just //www.eas.slu.edu ??. So I spent the day replacing the protorype leaf spring broadband with the "new, improved" BETA instrument on my pier in the basement. Of course its' too soon to evaluate it, but it seems to be continuing the 6-second microseism noise (from the storm off the east coast) and the local windy-day noise that the prototype was producing, and the calibration pulse still looks like that of a 90 second instrument. I will try to get sharper, clearer photos of it onto the web page. I've also been advised that html doesn't DO equations, so I'll scan the figures, graphics, and schematics for the paper and post them. Maybe tomorrow. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Marnie Gannon Subject: NPR- Volcano Date: Fri, 02 Jan 1998 11:02:47 -0700 Hey Guys.. taking a look around NPR archives..last weeks' Science Friday has an hour long report on volcanoes in realaudio..If you don't listen today then you will need to go to the archives..Go Here: http://www.npr.org/programs/totn/archives/scifricurrent.html Discussion with David Hill at Long Valley, Steve Malone of UW re Rainier and other Cascadia Volcanoes, and Jill Norton, chief scientist at Montserrat..also a call in section which touches on other US volcanoes.. Marnie _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Seisguy Subject: Fwd: Mexico Volcano Spews Ash, Lava Date: Fri, 2 Jan 1998 13:20:57 EST Happy New Year Popo! Now take some Tylenol and sleep it off.....;-) Mike 
Mexico Volcano Spews Ash, Lava


.c The Associated
Press


 MEXICO CITY (AP) - Hot ash rained on the outskirts of Mexico City when snow-
capped Popocatepetl volcano erupted for the second time in two weeks, spewing
glowing rock and smoke into the air.

The 18,000-foot volcano settled down 90 seconds after erupting Thursday
evening, and there were no reports of injuries or damage, officials told the
government news service Notimex.

Ash fell on nearby communities, and Notimex said the roar of the eruption
shook windows and doors of houses. Authorities said the eruption was
accompanied by a magnitude-3.5 earthquake.

The volcano 45 miles southeast of Mexico City last erupted on Dec. 24.

Government Ministry official Ricardo Garcia Villalobos was quoted by Notimex
as saying the smoke from the most recent blast rose two miles into the sky.

He said the blast was smaller than the June 30 eruption that shot a
40,000-foot plume of ash into the air, the biggest exhalation since 1925. It
coated Mexico City in ash, causing massive traffic jams.

Popocatepetl - which means ``smoking mountain'' in the language of the ancient
Aztecs - had been quiet for 70 years until periodic eruptions began in 1994.

AP-NY-01-02-98 0435EST


 Copyright 1997 The Associated
Press.  The information  contained in the AP news report may not be published,
broadcast, rewritten or otherwise distributed without  prior written authority
of The Associated Press. 


 

To edit your profile, go to keyword NewsProfiles.
For all of today's news, go to keyword News.
From: "David A. Nelson" Subject: Mt Ruapehu active Date: Sat, 03 Jan 1998 10:03:57 +1200 hi all, trust everyone has recovered from the festivities and there are not tooo many sore heads. :) just to let u know yesterday 02 Jan 98 New Zealand Mt ruapehu did 2 significant ash eruptions covering the mountain slopes with the fallout. These are the first for the last ~3 months cheers all Dave Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson ZL4TBN 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: SFBA PSN records for Mike Antolik Date: Fri, 02 Jan 1998 14:53:01 -0700 PSN members in the San Francisco Bay Area- 3-dimensional, finite-difference models of seismic wave propagation and site response in the San Francisco Bay Area created by members of the Seismic Station at UCB can be seen: http://www.seismo.berkeley.edu/seismo/events_of_interest/3dmod/3dmod.html -Edward -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: shammon1@............. Subject: Re: SFBA PSN records for Mike Antolik Date: Fri, 02 Jan 1998 18:45:07 -0800 Hi Ed, (and group) Great meeting-- I've been kind of slow in getting my act together because of the holidays... I have the film from the meeting at the local photo drop and as sonn I get it back and the scanner running again I'll post them to the San Jose PSN web site. I'll make an announcement on the PSN-List as soon as it done. QUESTION-- help me out here. When was the Alum Rock Quake? I lost my notes and I'm looking for the data you asked about. Regards, Steve Hammond PSN San Jose Edward Cranswick wrote: > > PSN members in the San Francisco Bay Area- > 3-dimensional, finite-difference models of seismic wave propagation and > site response in the San Francisco Bay Area created by members of the > Seismic Station at UCB can be seen: > > http://www.seismo.berkeley.edu/seismo/events_of_interest/3dmod/3dmod.html> > -Edward > > -- > Edward Cranswick Tel: 303-273-8609 > US Geological Survey, MS 966 Fax: 303-273-8600 > PO Box 25046, Federal Center cranswick@........ > Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Seisguy Subject: Re: SFBA PSN records for Mike Antolik Date: Fri, 2 Jan 1998 21:26:39 EST In a message dated 98-01-02 20:52:26 EST, you write: > QUESTION-- help me out here. When was the Alum Rock Quake? I lost my > notes and I'm looking for the data you asked about. > Steve, that M4.7 quake was May 21, 1996 @ 1:50pm. Regards, Mike O'Bleness Northridge, Ca _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: EMON CONFIGURATION Date: Fri, 02 Jan 1998 06:23:54 -0800 Hi Jim I asked Ted the same question several years ago. Plotting is done with points rather than lines to speed up the program sample rate. PSET is quicker than LINE. I don't know about the color. I have been viewing green on black for a while. I guess I got use to it. Barry RADIOTEL wrote: > > TO: BOB HAMMOND AND ALL LIST MEMBERS > > Thanks to the assistance of Bob Hammon I now have EMON up and running. I have > several questions: > 1. Is there a way to change the resolution? My screen shows a signal pattern > with > the dots Not Connected. I have changed the verticle compression of > displayed > signal to 20 and the horizonal to 15 which seemed to help somewhat. > 2. Is there a way to add color to the screen, even IBM Blue? > When the program saves the traces and I view it in Winquake the trace is good. > I am using EMON configured for the CIO-DAS08/Jr 12-bit A/D. > > Any suggestions would be appreciated. > Jim Allen > Cerritos, California _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: STM-8 documents Date: Fri, 2 Jan 1998 21:32:03 -0600 (CST) To those interested in the broadband leaf-spring vertical seis: I managed to get some of the drawings and schematics onto my web page at //www.eas.slu.edu/People/STMorrissey/index.html. It is still a bit disorganized, and it took me a while to figure out how to get readable documents without having giant files, but it is a start. ........ And Saturday is a good day to start gathering parts ...... Your comments and suggestions are, of course, welcome. The drawings are in .gif format. Someone advised me that I could put them out in .RTF format if someone's browser had the "plug in" too read it. Any comments? Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: RADIOTEL Subject: Re: EMON CONFIGURATION Date: Fri, 2 Jan 1998 22:48:21 EST TO: BARRY LOTZ Thanks for your assistance re. EMON. Jim Allen Cerritos, California _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: peaches@............ (Donna Whitaker) Subject: Kilauea Volcano Date: Fri, 2 Jan 1998 22:30:16 -1000 (HST) Hi all. Today, Jan 3 marks the 15th year of the Pu'u O'o eruption at Kilauea volcano on the Big Island of Hawaii. Here is the Hawaii Volcano Observatory (HVO) update URL which has their latest info and some nice picts. Enjoy and Aloha. http://hvo.wr.usgs.gov/geology/update2.html Tony Potenzo PSN Kona Station _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Doug Crice Subject: Pictures and drawings on the web Date: Sat, 03 Jan 1998 10:21:20 -0800 As a general rule, I think illustrations should be in either .GIF or ..JPG format, since virtually all browsers support these two standards for viewing. ..GIF is preferred for drawings, and will generally be most efficient for them. .GIF has only 256 colors, which keeps the size down. ..JPG (or jpeg) is preferred for photographs. It's a standard file compressing method which produces small files with lots of colors. If you want to get elegant, use progressive JIF and JPG, the kind of figures that appear full size then gradually get better as more of the file downloads. That way, the reader can either be entertained while he's waiting or go on if he's not interested. There is a pretty good graphics/photo editing program Lviewpro which can create these formats from others, available for download from http://lview.com/ Doug Crice _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: John Hernlund Subject: Re: Pictures and drawings on the web Date: Sat, 03 Jan 1998 11:57:23 -0700 (MST) On Sat, 3 Jan 1998, Doug Crice wrote: > As a general rule, I think illustrations should be in either .GIF or > .JPG format, since virtually all browsers support these two standards > for viewing. I think .tiff files are supported for Netscape on all platforms now as well, though I don't use them very often. > .JPG (or jpeg) is preferred for photographs. It's a standard file > compressing method which produces small files with lots of colors. > There is a pretty good graphics/photo editing program Lviewpro which can > create these formats from others, available for download from > http://lview.com/ This is true indeed. But I haven't yet found a program better than Adobe Photoshop for every graphics task. JPEGs have an option which you can control which is the compression of the graphic, which is something you can play with when saving a JPEG in Photoshop. But the accuracy of the image decreases with the amount of compression so that what you are seeing as you compress it more and more is only an approximation of the original. However, for most people browsing in 256 colors or even thousands of colors this difference is almost entirely undetectable. But then again, nothing beats the crispness of a less compressed, well-scanned photo while viewing in 32-bit true RGB. My best result of this can be seen in a photo of Superstition Mountain near Mesa I have posted to my web site. The URL is http:/www.public.asu.edu/~hernlund/ Sure, Photoshop can be expensive if you buy it yourself, but it is worth every penny. This software has also been invaluable to scientific research based on digital images (Hubble, etc.) due to all the manipulation tools and macros/filters it supports. ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: coil winding,etc Date: Sat, 3 Jan 1998 13:02:07 -0600 (CST) Jim, Before you wind your coil with 1/2 pound of # 34 wire, here are some considerations. That amount of #34 has a resistance of 1084 ohms at room temperature, which is way too much if you intend to use it for a feedback coil. I would suggest using much larger wire, not only to reduce the resistance, but to create a stronger electromagnet for use as a feedback or force coil. (This should not be confused with the voltage produced by moving a coil in a magnetic field, in which the more the turns, the greater the voltage.) For example, if you use #30, it has 170 ohms / 1/2 lb; however, it has a cross section of 0.000079 sq.", whereas the #34 is 0.000031. So the #30 has about 2.5 times the area, meaning that in the same coil form it will give 1/2.5 (0.4) times the number of turns. But the resistance of #30 is 1/6.4 (0.16) x that of #34. The strength of an electromagnet is determined by the Ampere-turns (# turns x current); so even if you get only 0.4 of the turns, with 0.16 of the resistance, you have 6.4 times the current for the same voltage, or 0.4/0.16 = 2.5 times the Ampere-turns or field strength. Going even further, #24 wire has 1/10 the cross section of #34, but only 10.5 ohm/0.5 lb, or 1/100th that of #34. so the induced field will be 10x stronger. This is why stereo speakers have such low resistances. Regarding the natural period of your seismometer; I am confused by your mention of 100 and 600 seconds; I guess that these are the length of the decay time of the free oscillations, and not the natural period. The natural period will range from less than 1 to more than 20 seconds for most mechanical systems. It is determined by measuring the time of, say, 10 oscilations, with a stopwatch and dividing. If the system has minimal frictional or air damping, it should oscillate a few mm for at least a minute or two. If you have the lower end of the leaf spring clamped to the base, it will force the natural period to be very short. Both ends of the spring must be able to flex, ie. follow the curvature of the whole spring. When the ends are about 5.5 to 6" apart, it starts to exhibit "zero length" behavior, where the restoring force is constant for small changes in length. At this point very long periods, even instability, are realized. This is achieved with coil springs by twisting the wire as it is coiled, so the spring requires a large initial force just to open it, which is why this type of spring is used for vertical seismometers. I am working on a writeup of the details of the leaf-spring installation; I will send you a draft later today. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: frankcnd@.......... (Frank Condon) Subject: The Latest Swarm in Mammoth Date: Sat, 3 Jan 1998 11:23:56 -0800 (PST) Hello All: Here is an updated CURRENT CONDITION report on Mammoth Lakes from the official USGS Long Valley Caldera Web Site: -------------------------------------------------------------------- Caldera activity: The gradual decay in the level of earthquake swarm associated with the M=4.8 earthquake of December 31 was interrupted with a slight increase in activity in the early hours of Jan. 3. This activity, which continues to be concentrated in the area between the airport and fish hatchery (5 to 7 miles E of Mammoth Lakes), included three earthquakes of magnitude M=3.0 or greater: a pair of M=3.0 events at 2:19 AM and 2:57 AM respectvely, and a M=3.2 event at 3:38 AM. The realtime computer system detected and located some 250 events over the past 24 hours, nine of which had magnitudes of M=2.5 or greater (including the three M>3 events mentioned above). The resurgent dome continues to inflate at about the same rate as observed in late-October and early November. -------------------------------------------------------------- Frank Condon mail to:frankcnd@.......... "Located in the seismic corridor somewhere between Fontana & Mammoth Lakes" _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: STM-8 documents Date: Sat, 03 Jan 1998 00:36:26 -0800 Sean Thomas I appreciate your effort. GIF is was ok for me. I used paintshop pro and had good resolution. I only had problems with the horizontal scale on the graphs (clipped) but I was more interested in the schematics. I have been looking for awhile for documentation that would increase the effective period of a sensor electronically. I am in the process of trying to take your feedback ideas and incorporating it with the vertically hung horizontal sensor (Like the SG suspension- less problem with drift than my long period garden gate Lehman). I'll let you know how it goes. I am currently trying to center the Radio Shack coil in the magnet with only a 8" sensor arm. Thanks again for your efforts. Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Tobin Fricke" Subject: Re: Pictures and drawings on the web Date: Sat, 3 Jan 1998 11:35:12 -0800 > I think .tiff files are supported for Netscape on all platforms now as >well, though I don't use them very often. I'd stay away from TIFF files on the web. If a web browser supports images at all, it will support GIF, and most likely JPG. Version 4 browsers have some support for PNG, an excellent format. Photographs should use JPG Drawings and diagrams should use GIF Tobin _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Your Name Subject: Solder Geophone Terminals??? Date: Sat, 03 Jan 1998 12:11:11 -0800 Can you solder directly to the two little terminals on top of a GS-11D geophone without messing up the sensor??? Thanks! Roger - KD6LQE _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: Re: Solder Geophone Terminals??? Date: Sat, 3 Jan 1998 14:53:22 -0600 (CST) Roger, Yes you can solder to the terminals, but with a relatively small solder pencil. The current in the tip of a solder gun may demagnetize the magnet of the little geophone. The damping resistor is usually soldered across the terminals. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "David A. Nelson" Subject: Re: Solder Geophone Terminals??? Date: Sun, 04 Jan 1998 10:02:38 +1200 At 12:11 PM 1/3/98 -0800, you wrote: >Can you solder directly to the two little terminals on top >of a GS-11D geophone without messing up the sensor??? >Thanks! Roger - KD6LQE Yes no trouble at all, al of the ones I have inastalled aroind the place i have soldered to without any problem. The sensor is very robust. like any thing electronic that u solder DONT linger there with the soldering bolt get the joint done and let it cool cheers Dave Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson ZL4TBN 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Norman Davis WB6SHI Subject: Geophone Date: Sat, 03 Jan 1998 15:45:02 I just got a copy of rtclark cataloge. There are two types of geophones. One is called shearwave and the other nothing. I asume the lower freq the better. What kind do I want? Norman Davis WB6SHI Email normd@............. Shingle Springs, Ca, USA it ain't local... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Roger Sorensen Subject: Re: Geophone Date: Sat, 03 Jan 1998 16:40:13 -0800 Norman Davis WB6SHI wrote: > > I just got a copy of rtclark cataloge. There are two types of geophones. > One is called shearwave and the other nothing. I asume the lower freq the > better. > What kind do I want? > > Norman Davis WB6SHI > Email normd@............. > Shingle Springs, Ca, USA it ain't local... Well I'm no expert, but from what I understand "shearwave" is a horizontal sensor while the other "no name" is a vertical sensor. I think in our application, the lower the freq. is the better. I just got my GS-11D geophone in the ground and it seems to work pretty well. Best of luck with yours. Roger - KD6LQE Chatsworth, CA, USA (34.16.23 118.35.62) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Charlie Rond Subject: Re: EMON CONFIGURATION Date: Sat, 03 Jan 1998 19:48:03 -0600 Jim, From my perspective, the Ted Blank software is really a package of components. EMON, of course, is the data monitoring module, QUAKEVIEW (or QUAKEVU) is the display module for a single seismogram, EL lists a group of seismograms for QUAKEVIEW to display, MSPLICE is a utility to "glue" together several files representing a single quake, HOWFAR calculates great circle distance to an epicenter from latitude and longitude, and there are other utilities. If QUAKEVIEW is present, one can display a recorded seismogram from within EMON merely by pressing F8 (and delete, annotate, etc.). The recording can be displayed as a series of data points - as you see on the screen in EMON - or with dots connected by lines (as in WINQUAKE) to any degree of horizontal or vertical compression, etc. P and S points can be picked, comments added, the recording modified and so on. If you have a lot of data files accumulated, EL (QUAKEVIEW) is the fastest way to quickly scan them. My point is that you are not fully utilizing EMON unless you also are using QUAKEVIEW (and EL). As to color: I think the answer is no. By the way, I'm not an "agent" for Ted Blank. I just think he and Larry Cochrane have provided us with some superb software we rarely exploit to full capacity. I'm running both EMON and SDR on different setups and couldn't do without either. --Charlie Rond >> TO: BOB HAMMOND AND ALL LIST MEMBERS >> >> Thanks to the assistance of Bob Hammon I now have EMON up and running. I have >> several questions: >> 1. Is there a way to change the resolution? My screen shows a signal pattern >> with >> the dots Not Connected. I have changed the verticle compression of >> displayed >> signal to 20 and the horizonal to 15 which seemed to help somewhat. >> 2. Is there a way to add color to the screen, even IBM Blue? >> When the program saves the traces and I view it in Winquake the trace is good. >> I am using EMON configured for the CIO-DAS08/Jr 12-bit A/D. >> >> Any suggestions would be appreciated. >> Jim Allen >> Cerritos, California > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) ---------------------------------------------------------------------- Charlie Rond -\/\--Public Seismic Network-Memphis rond@................ (901) 360-0302 [ free BBS ] http://gandlf.ceri.memphis.edu/~rond http://gandlf.ceri.memphis.edu/~rond/psn _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: James Subject: Mammoth Lakes question Date: Sat, 3 Jan 1998 20:36:32 -0600 (CST) Some people explain some "ufo" sightings as ball lightning caused by earthquakes. Are any reports of "lights" coming from Mammoth Lakes? _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: RADIOTEL Subject: Re: EMON CONFIGURATION Date: Sat, 3 Jan 1998 21:44:49 EST TO: CHARLIE ROND Thanks for your advice. I will certainly followup on those suggestions. Jim Allen Cerritos, California _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Bill Scolnik Subject: Re: Rockland filter Date: Sat, 3 Jan 1998 22:34:15 -0500 (EST) At 09:16 AM 1/1/98 -0500, Robert L Barns wrote: > Hi gang, > Here's something you might look for at a hamfest or on used equipment >lists. I find it a very useful accessory to my Lehman. I got it from Bill >Scolnic. He found it at a hamfest. He uses a Kron-Hite filter which I >think is quite similar. I'm guessing that $100 or so might get one or the >other at a hamfest. > It is a Rockland Systems Corp. adjustable filter, Model 1022F. It is in >a 19" rack mount case 5 1/2" high and is not very heavy. It contains 2 >identical sections and the data below are for each section. > I don't have the manual so the data are my measurements. A switch >selects either low or high pass. There are 3 decimal dials (X.XX) and a >1X, 10X, 100X and 1000X range switch. This allows setting the knee >frequency from 0.01Hz to 9,990 Hz! A switch selects either 0 or 20db gain. > With the knee frequency set at either 0.08Hz or 200Hz, I found that the >slope above the knee of the low pass filter is 24db/octave with no vis. >ripple. Who could ask for anything more? > The output is from DC with an offset in the output of about 5 mV and I >saw no clipping with output voltages up to 9V. The input impedence is 1 >megohm. There is a switch for each section labelled BW-AC. Can anyone >explain this switch? > I don't know the vintage but found it interesting that the active >components look to be all transistors-no op-amps. When I got it, the left >section worked fine but the right section was a mess. Each section >consists of 5 or 6 small (3X4" about) plug-in cards. I started to >troubleshoot the right section by swapping these cards from section to >section but I discovered that one of the cards in the right section was >plugged-in BACKWARDS. Putting this in the right way fixed it. > Since I have only one seismometer, I'm using it set at 0.08Hz with the >two sections in series so that the slope above the knee is 48db/octave. >With my old home-made 6-pole 0.08Hz filter, I could always see some of the >noise peak at 0.016Hz. With 48 db/octave, this peak is not seen. > A filter which is so easily adjusted opens the door to various >experiments. >Happy hunting & Happy New Year! >Bob Barns > > Bob, The BW/AC switch most likely changes the filter configuration from Butterworth to RC. Bill Scolnik > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: Re: VBB Integrator Date: Sat, 3 Jan 1998 23:26:44 -0600 (CST) Barry et al, Your observation of the non-inverting integrator configuration is correct. It is true that most integrators are inverting, but this is just a hangover from early op-amp circuits where everything was using the inverting input. Of course, it is also a low-pass filter of one pole, and is even described in the literature as a "unit-lag" or "running-mean" amplifier. The response of an inverting integrator is: Eout = - 1/(RC)*integral [( Ein - Eout )dt]. It is the same for the non-inverting config, except without the "-" The time constant is R(ohms) x C (farads) in seconds. IF it WERE considered a filter, then the Fc would be 2*pi*R*C, as you observed. But our transfer function needs the time constant, which is actually in radians/second. As for using a single amplifier, a very low input offset and leakage current unit will work, something like the OPA111. I use the instrumentation configuration because with affordable large capacitors (ie electrolytics), leakage currents vary with temperature, etc, and I am trying to minimize all known noise sources. (I also have a box of them left over from monitoring earth currents in the Aleutians, which the Greeks claimed could predict quakes; just a bunch of noise, though). Also the two 2meg resitors should have a low a temp coefficient and be carefully matched so the amp input currents don't vary with temperature. And, of course, it does work as advertised in the 6 VBB circuits I am running with it. I do appreciate the feedback needs for clarifications. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "David A. Nelson" Subject: MAJ EVENT Date: Sun, 04 Jan 1998 19:22:58 +1200 time 06 22 utc 04 jan 98 maje event coming in Dave Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson ZL4TBN 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: MA EVENT Date: Sat, 03 Jan 1998 22:34:33 -0800 Amazing, your message arrived about 30 seconds before the P wave arrived here... I was setting at my computer and your message arrived. After reading it, I looked over at my SDR systems and saw nothing. Then all of a sudden the alarm went off.... No S wave yet. -Larry At 07:22 PM 1/4/98 +1200, Dave Nelson wrote: > >time 06 22 utc 04 jan 98 maje event coming in > > >Dave _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Tom Frey" Subject: Re: MA EVENT Date: Sat, 3 Jan 1998 22:45:23 -0800 Same Here!!!! _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Ron Westfall Subject: Re: MA EVENT Date: Sat, 03 Jan 1998 22:42:28 -0800 Hi The S waves reached Vancouver, BC about 3 - 4 minutes ago. They are still coming in. Ron Westfall Larry Cochrane wrote: > Amazing, your message arrived about 30 seconds before the P wave arrived > here... I was setting at my computer and your message arrived. After > reading it, I looked over at my SDR systems and saw nothing. Then all of a > sudden the alarm went off.... No S wave yet. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: watson@................ (Charles Watson) Subject: Re: Monster Quake? Date: Sat, 03 Jan 1998 22:49:24 -0700 Any word on where it was yet? -- ---/---- Charles P. Watson, Consulting Geologist Advanced Geologic Exploration Seismo-Watch / Earthquake Information Services Voice: 702-852-0992 / Fax: 702-852-3226 Office Location: 39.43N 119.71W mailto:watson@................ http://www.seismo-watch.com _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "frank murray" Subject: RE: MA EVENT Date: Sat, 3 Jan 1998 22:49:14 -0800 if everybody could pop their times and locations into their posts, we could all see the pattern of the waves... > -----Original Message----- > From: Tom Frey [mailto:tfrey@............ > Sent: Saturday, January 03, 1998 10:45 PM > To: PSN-L Mailing List > Subject: Re: MA EVENT > > > Same Here!!!! > > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Ron Westfall Subject: Re: MA EVENT Date: Sat, 03 Jan 1998 22:59:41 -0800 Hi Vancouver, BC, Canada P: approx. 6:25:00 S: approx. 6:35:45 Ron Westfall frank murray wrote: > if everybody could pop their times and locations into their posts, we could > all see the pattern of the waves... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "David A. Nelson" Subject: Re: MA EVENT Date: Sun, 04 Jan 1998 20:03:29 +1200 ok larry and i actually was ~4 minutes into the event when i mailed u guys tooo bust watching the event come in to mail sooner Dave At 10:34 PM 1/3/98 -0800, you wrote: >Amazing, your message arrived about 30 seconds before the P wave arrived >here... I was setting at my computer and your message arrived. After >reading it, I looked over at my SDR systems and saw nothing. Then all of a >sudden the alarm went off.... No S wave yet. > >-Larry > >At 07:22 PM 1/4/98 +1200, Dave Nelson wrote: >> >>time 06 22 utc 04 jan 98 maje event coming in >> >> >>Dave > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson ZL4TBN 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "John Krempasky" Subject: Re: MA EVENT Date: Sun, 4 Jan 1998 02:07:13 -0500 Hmm, interesting, I've been surfing around, nothing on NEIC, this is what I've found so far (I presume this is the seismo) from the Swiss network; they don't have a loc yet. Off the scale, I guess, yes? http://seismo.ethz.ch/networks/telemetry_net/signals/KP199801040631.gif _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Tom Frey" Subject: Re: MA EVENT Date: Sat, 3 Jan 1998 23:12:00 -0800 P approx 06:25:07 @ RM1 (47.456N, 121.803W) 06:25:06 @ GM1 (47.202N, 121.790W) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: MAJ EVENT Date: Sat, 03 Jan 1998 23:11:58 -0800 At 10:59 PM 1/3/98 -0800, you wrote: >Hi > > Vancouver, BC, Canada > P: approx. 6:25:00 S: approx. 6:35:45 Redwood City, Ca USA P: 6:24:50 S: 6:35:20 Based on a depth of 33km distance = 9559km from station and a time of origin of 6:12:12UTC. Magnitude over 7 -Larry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "David A. Nelson" Subject: Re: MA EVENT Date: Sun, 04 Jan 1998 20:11:34 +1200 im posting my event file in a couple of minutes get my p arrival off there Dave At 10:59 PM 1/3/98 -0800, you wrote: >Hi > > Vancouver, BC, Canada > P: approx. 6:25:00 S: approx. 6:35:45 > >Ron Westfall > >frank murray wrote: >> if everybody could pop their times and locations into their posts, we could >> all see the pattern of the waves... > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson ZL4TBN 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: watson@................ (Charles Watson) Subject: Once again, it's Vanuatu Islands! Date: Sat, 03 Jan 1998 23:15:11 -0700 Once again, it's Vanuatu Islands! -- ---/---- Charles P. Watson, Consulting Geologist Advanced Geologic Exploration Seismo-Watch / Earthquake Information Services Voice: 702-852-0992 / Fax: 702-852-3226 Office Location: 39.43N 119.71W mailto:watson@................ http://www.seismo-watch.com From: Ray Gallagher Subject: Re: MA EVENT Date: Sat, 03 Jan 1998 23:17:07 -0800 e0208c0-w- d o NWS-TSUNAMI-BULLETIN-NUM 01-03 0167 TSUNAMI BULLETIN NUMBER 1 WEST COAST AND ALASKA TSUNAMI WARNING CENTER/NOAA/NWS ISSUED JAN 4 AT 0655 UTC ..THIS IS A TSUNAMI INFORMATION BULLETIN FOR ALASKA, BRITISH COLUMBIA, WASHINGTON, OREGON, AND CALIFORNIA ONLY... NO, REPEAT NO, WATCH OR WARNING IS IN EFFECT. AN EARTHQUAKE, PRELIMINARY MAGNITUDE 7.0, OCCURRED AT 2112 AST ON JAN 3, OR 2212 PST ON JAN 3, OR 0612 UTC ON JAN 4. THE EARTHQUAKE WAS LOCATED IN THE GENERAL AREA OF: SOUTH OF VANUATU NEAR 22.1S, 170.7E. THE PACIFIC TSUNAMI WARNING CENTER WILL ISSUE A TSUNAMI INFORMATION BULLETIN FOR HAWAII AND OTHER AREAS OF THE PACIFIC. EVALUATION: BASED ON LOCATION AND MAGNITUDE THE EARTHQUAKE WAS NOT SUFFICIENT TO GENERATE A TSUNAMI DAMAGING TO CALIFORNIA, OREGON, WASHINGTON, BRITISH COLUMBIA OR ALASKA. SOME AREAS MAY EXPERIENCE SMALL SEA LEVEL FLUCTUATIONS. THIS WILL BE THE ONLY BULLETIN ISSUED FOR THIS EVENT BY THE WEST COAST AND ALASKA TSUNAMI WARNING CENTER UNLESS CONDITIONS WARRANT.IF AVAILABLE, REFER TO THE INTERNET SITE (USE LOWER CASE) HTTP://WWW.ALASKA.NET/(TILDA)ATWC FOR MORE INFORMATION. EDIS-01-03-98 2257 PST _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Ray Gallagher Subject: Re: MA EVENT Date: Sat, 03 Jan 1998 23:17:43 -0800 e0209c0-w- d o NWS-TSUNAMI-BULLETIN-NO. 01-03 0141 TSUNAMI BULLETIN NO. 001 PACIFIC TSUNAMI WARNING CENTER/NOAA/NWS ISSUED AT 0701Z 04 JAN 1998 THIS BULLETIN IS FOR ALL AREAS OF THE PACIFIC BASIN EXCEPT CALIFORNIA, OREGON, WASHINGTON, BRITISH COLUMBIA, AND ALASKA. . THIS IS A TSUNAMI INFORMATION MESSAGE, NO ACTION REQUIRED . . AN EARTHQUAKE, PRELIMINARY MAGNITUDE 7.0 OCCURRED AT 0612 UTC 4 JAN 1998, LOCATED NEAR LATITUDE 22S LONGITUDE 171E IN THE VICINITY OF LOYALTY ISLANDS REGION EVALUATION: A PACIFIC-WIDE TSUNAMI WAS NOT GENERATED BASED ON EARTHQUAKE AND HISTORICAL TSUNAMI DATA. THIS WILL BE THE ONLY BULLETIN ISSUED UNLESS ADDITIONAL INFORMATION BECOMES AVAILABLE. . . NO PACIFIC-WIDE TSUNAMI WARNING IS IN EFFECT . . . RECIPIENTS OF THIS MESSAGE LOCATED IN CALIFORNIA, OREGON, WASHINGTON, BRITISH COLUMBIA, AND ALASKA SHOULD REFER ONLY TO ALASKA TSUNAMI WARNING CENTER MESSAGES FOR INFORMATION ABOUT ANY TSUNAMI THREAT IN THOSE AREAS. EDIS-01-03-98 2302 PST _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "David A. Nelson" Subject: vanuatu .... Date: Sun, 04 Jan 1998 20:47:43 +1200 i have a ham radio friend in vanuatu have jst emailed him to see if he felt it will let u know what he says cheers Dave BTW these are the largest P waves i have EVER recorded from this area will be interesting to see the final USGS report have a feeling the Mw will tell the real truth Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson ZL4TBN 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Canie Brooks Subject: Loyalty Islands Date: Sun, 04 Jan 1998 00:03:40 -0800 This is the URL for the event on IDC List: http://www.cdidc.org:65120/web-bin/event/bulletin=AELs/evids=1248641/map_sca le=2 (BTW: Can anyone explain why they are always lower in magnitude than USGS?) Canie _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "David A. Nelson" Subject: Re: Loyalty Islands Date: Sun, 04 Jan 1998 21:15:12 +1200 At 12:03 AM 1/4/98 -0800, you wrote: >This is the URL for the event on IDC List: >http://www.cdidc.org:65120/web-bin/event/bulletin=AELs/evids=1248641/map_sca >le=2 > >(BTW: Can anyone explain why they are always lower in magnitude than USGS?) > >Canie it is a computer generated report mate they are ALLWAYS extremely low cheers DAve Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson ZL4TBN 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Francesco Subject: BIG QUAKE Date: Sun, 04 Jan 1998 10:15:18 +0100 Hi to all, the italian station have registered at 6.33 Utc a big quake. Large P non S and Surface wave. Preliminary location Sud Est Pacific (LOyalty Islands???) Ms =>6.9 Good Day Francesco FRANCESCO NUCERA OSIMO - Ancona - ITALY Lat. 43 29" E - Long. 13 29" E _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Stephen Paul Subject: Re: MA EVENT Date: Sun, 04 Jan 1998 02:13:31 -0800 Larry Cochrane wrote: > Amazing, your message arrived about 30 seconds before the P wave arrived > here... I was setting at my computer and your message arrived. After > reading it, I looked over at my SDR systems and saw nothing. Then all of a > sudden the alarm went off.... No S wave yet. > > -Larry > > At 07:22 PM 1/4/98 +1200, Dave Nelson wrote: > > > >time 06 22 utc 04 jan 98 maje event coming in > > > > > >Dave > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L Larry, did you or nyone else pick up something around 1-1:30 PST? I felt a fairly muted but strong tremor in the Sherman Oaks area of So. CA this morning, and went online a bit later to see if there was any news, and lo and behold, you magic Indians had your ears to the ground! Not surprising, I was just wondering if this might be related... We get a lot of these up in the hills, very close along the line of the Northridge fault that took part of this area down in '94... Thanks, (I did get an S wave in my seat at the time...). -- Stephen Paul :^) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Stephen Paul Subject: Re: MA EVENT Date: Sun, 04 Jan 1998 02:16:52 -0800 Larry, Actually I see by the time that these messages started appearing, it could have been earlier. I was immersed in a film and stupidly neglected to note the time... I'm sure it must be related. Any news yet? - Stephen :^) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Stephen Paul Subject: Re: MA EVENT Date: Sun, 04 Jan 1998 02:19:39 -0800 frank murray wrote: > if everybody could pop their times and locations into their posts, we could > all see the pattern of the waves... > > > -----Original Message----- > > From: Tom Frey [mailto:tfrey@............ > > Sent: Saturday, January 03, 1998 10:45 PM > > To: PSN-L Mailing List > > Subject: Re: MA EVENT > > > > > > Same Here!!!! > > > > > > Tom, As I mentioned to Larry, I didn't get the time, but my house really swayed down here in Sherman Oaks, San Fernando Valley area of So. CA -- Stephen Paul :^) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Stephen Paul Subject: Re: MA EVENT Date: Sun, 04 Jan 1998 02:38:31 -0800 I now have checked with my girlfriend and I'm not as crazy as I thought... we actually had a quake down here in So. CA over two hours later... Could these possibly be related? Kate Hutton would tell me that there's no relationship as they're too far away from each other... but I wonder... there's that ringing bell again? -- Stephen :^) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: STM-8 documents Date: Sun, 4 Jan 1998 09:49:55 -0500 Sean-Thomas, I would suggest staying with .GIF format since more people can easliy view this brand of graphics. Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: watson@................ (Charles Watson) Subject: Fwd: Caltech's CMT for the Loyality Is. quake Date: Sun, 04 Jan 1998 08:12:41 -0700 Attached below is Caltech's Automatic Centroid Moment Tensor solution for the Loyalty Islands event. It was centered pretty darn close to the intersection of the Hebrides subduction zone and the Hunter Ridge. The orientation of the focal mechanism, however, suggests a better relationship with the Hunter Ridge zone. There was a M7.7 near here on May 16, 1995 - centered slightly closer to Walpole Island. -- ---/---- Charles P. Watson, Consulting Geologist Advanced Geologic Exploration Seismo-Watch / Earthquake Information Services Voice: 702-852-0992 / Fax: 702-852-3226 Office Location: 39.43N 119.71W mailto:watson@................ http://www.seismo-watch.com From: "Martin Brewer" Subject: Re: MA EVENT Date: Sun, 4 Jan 1998 00:20:33 -0400 Hello All, Bermuda recorded the Loyalty Islands Region earthquake at a distance of 130 degrees away. What appears to be a SkP arrived at 06:34:33. There was no obvious P wave equivalent. Martin _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: VBB integrator Date: Sun, 4 Jan 1998 11:02:32 -0600 (CST) Barry, I forgot to mention one detail about the integrator: why I use a non-inverting configuration: For the VBB feedback, the integral feedback thru RI can not be inverted with respect to the proportional or differential feedbacks, so if an inverting integrator is used, an additional inverter amp is required between the displacement transducer amp/filter and the inverted integrator input. (This is done on commercial units that provide a full differential output of the VBB signal for 1 bit more of dynamic range.) I stay with a "single ended" system for simplicity. Regards, Sean-THomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Karl Cunningham Subject: Re: MA EVENT Date: Sun, 04 Jan 1998 09:05:57 -0800 Stephen -- I just uploaded my event file for your felt earthquake... 98/01/04 09:11:45 34.20N 118.62W 0.0 3.2ML 1 mi W of CANOGA PARK Karl Cunningham La Mesa, CA. PSN Station #40 karlc@....... At 02:13 AM 1/4/98 -0800, Stephen Paul wrote: > Larry, did you or nyone else pick up something around 1-1:30 PST? I felt a >fairly muted but strong tremor in the Sherman Oaks area of So. CA this >morning, and went online a bit later to see if there was any news, and lo and >behold, you magic Indians had your ears to the ground! Not surprising, I was >just wondering if this might be related... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: frankcnd@.......... (Frank Condon) Subject: The Current Status of Mammoth Date: Sun, 4 Jan 1998 10:51:27 -0800 (PST) Hello All: Here is the latest information about the CURRENT CONDITION of the Mammoth Lakes (Long Valley) caldera as posted by the USGS on their Web Site. ---------------------------------------------------------- Caldera activity: Earthquake activity within the caldera over the past 24 hours included four earthquakes with magnitudes greater than M=3.0. On the evening of the 3rd, M=3.6 and M=3.4 events at 10:19 PM and 10:25 PM, respectively, were located 5 miles east of Mammoth Lakes (near the mouth of Fumarole Valley). On the morning of the 4th, M=3.2 and M=3.6 events at 4:29 AM and 4:34 AM, respectively, were located 2 miles ESE of Mammoth Lakes. All together, 306 earthquakes were detected and located by the realtime computer system over the past 24 hours. Seventeen of these (including the four M>3 earthquakes) had magnitudes of M=2.5 or greater. Most of these earthquakes were located in the south moat from the vicinity of fish hatchery to east of the airport (5 to 7 miles E of Mammoth Lakes) with a smaller number in a cluster just 2 miles ESE of Mammoth Lakes. The resurgent dome continues to inflate at about the same rate as observed in late-October and early November. ---------------------------------------------------------- Frank Condon mail to:frankcnd@.......... "Located in the seismic corridor somewhere between Fontana & Mammoth Lakes" _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Marnie Gannon Subject: ISAIAH AUTOMATIC DATA SUMMARY FOR EVENT ID=9038429 Date: Sun, 04 Jan 1998 12:47:11 -0700 Hey Guys, could you tell me what this is, in easy speak? Thanks, Marnie http://www-socal.wr.usgs.gov/given/review/quakes/9038429_sum.html From: shammon1@............. Subject: Re: ISAIAH AUTOMATIC DATA SUMMARY FOR EVENT ID=9038429 Date: Sun, 04 Jan 1998 14:53:30 -0800 This is the Southern Californa automatic earthquake locator system. It is an example of the state of the art in cool web pages. Take a look at http://www-socal.wr.usgs.gov/given/review/quakes/9038516_sum.html because it also includes the event data which is missing on the URL you posted. I'm told that it is also tied to a pager system but I've yet to so one. Maybe somebody has more information. Regards, Steve Hammond PSN BBS San Jose Marnie Gannon wrote: > > Hey Guys, could you tell me what this is, in easy speak? > Thanks, Marnie > http://www-socal.wr.usgs.gov/given/review/quakes/9038429_sum.html > > --------------------------------------------------------------- > > ISAIAH AUTOMATIC DATA SUMMARY FOR EVENT ID=9038429 > > ON THIS PAGE, JUMP TO... > > [Seismograms] [Notification Message] [Solution Output] [Phase Listing] > [Return to TOP] > > [BACK TO EARTHQUAKE LIST] > > Seismograms of closest stations (sorted by distance) > ---------------------------------------------------------------------- > > [Image] > > WHAT THE PLOT SHOWS: > > * Closest 15 sites with phase picks > * 60 Seconds of time > * Event origin time is 10 sec after beginning of plot > > [Seismograms] [Notification Message] [Solution Output] [Phase Listing] > [Return to TOP] > > [BACK TO EARTHQUAKE LIST] > > ---------------------------------------------------------------------- > > Notification message > > ---------------------------------------------------------------------- > > == PRELIMINARY REPORT OF SIGNIFICANT EVENT == > Southern California Seismographic Network operated by USGS and Caltech > (This is a computer generated solution and has not been reviewed by a human) > > Event Date and Time : 04-JAN-1998 09:32:40.5 gmt (04-JAN 01:32:40.5 pst) > Preliminary Magnitude: 2.2 MGN > Preliminary Location : 35 deg. 37.0 min. > -120 deg. 30.4 min. -6.0 km depth > > Event ID #: 9038429 , 8 phases used, RMS = 0.63 ERH = 2.50 ERZ = 52.50 > > 20 mi. SSW of PARKFIELD > 168 mi. NW of PASADENA > 14 mi. NNE of SANTA-MARGARITA (quarry) > 21 mi. S of Parkfield EQ (28 JUN 1966, 5.6) > 9 mi. WNW of the RINCONADA FAULT > > [Seismograms] [Notification Message] [Solution Output] [Phase Listing] > [Return to TOP] > > [BACK TO EARTHQUAKE LIST] > > ---------------------------------------------------------------------- > > HYPOINVERSE solution output > > ---------------------------------------------------------------------- > > ERROR ELLIPSE: -< 52.50 0 90>-< 2.50 226 0>-< 1.77 316 0> > ------------------------------------------------------------------------------------ > YR MO DA --ORIGIN-- --LAT N- --LON W-- DEPTH RMS ERH ERZ XMAG FMAG > 98- 1- 4 0932 40.48 35 36.99 120 30.40 6.00 0.63 2.50 52.50 > SOURCE > NSTA NPHS DMIN MODEL GAP ITR NFM NWR NWS NVR REMRKS N.XMG-XMMAD-T N.FMG-FMMAD-T L F X > 11 11 50.7 HAD 121 14 0 8 0 11 - 0.00 0.00 0.00 0.00 > REGION= FALX LOCATION: 9038429 > > STA CR DIST AZM AN P/S WT SEC (TOBS -TCAL -DLY =RES) WT SR INFO CAL DUR-W-FMAG-T AMP-PER-W-XMAG-T RMK > PBI 50.7 176 90 P 49.71 9.23 8.53 0.00 0.70* 1.05 0.313 > PSM 51.0 351 90 P 1 50.43 9.95 8.58 0.00 1.37* 0.66 0.240 > PPB 52.3 221 90 P 49.65 9.17 8.79 0.00 0.38 1.05 0.472 > YEG 53.3 112 90 P 49.67 9.19 8.94 0.00 0.25 1.05 0.705 > SIM 54.8 122 90 P 49.66 9.18 9.18 0.00 0.00 1.05 0.930 > PHC 58.9 278 90 P 49.65 9.17 9.84 0.00 -0.67* 1.05 0.470 > PRI 60.1 347 90 P 50.37 9.89 10.03 0.00 -0.14 1.05 0.580 > BCH 61.2 141 90 P 49.68 9.20 10.20 0.00 -1.00* 1.05 0.286 > PTQ 115.3 183 90 S 70.55 30.07 33.43 0.00 -3.36* 0.00S 0.000 > MTU 261.0 42 53 P 70.59 30.11 38.53 0.00 -8.42* 0.00 0.000 > MTC 263.9 31 53 P 70.67 30.19 38.90 0.00 -8.71* 0.00 0.000 > > [Seismograms] [Notification Message] [Solution Output] [Phase Listing] > [Return to TOP] > > [BACK TO EARTHQUAKE LIST] > > ---------------------------------------------------------------------- > > Phase picks (HYPOINVERSE format) > > ---------------------------------------------------------------------- > > PHC IPU0 98 1 4 93249.65 P VHZ 1225 0 > PPB IPD0 98 1 4 93249.65 P VHZ 1094 0 > YEG IPD0 98 1 4 93249.67 P VHZ 952 0 > SIM IPU0 98 1 4 93249.66 P VHZ 742 0 > BCH IPU0 98 1 4 93249.68 P VHZ 1026 0 > PBI IPU0 98 1 4 93249.71 P VHZ 2132 0 > PSM IPU1 98 1 4 93250.43 P VHZ 625 0 > PRI IPD0 98 1 4 93250.37 P VHZ 1019 0 > PTQ 98 1 4 933 10.55ISD0 S VHZ 1322 0 > MTC IPU0 98 1 4 93310.67 P VLZ 1722 0 > MTU IPU0 98 1 4 93310.59 P VHZ 767 0 > 932404835 3699120 3040 6.00 9038429 9038429 0.00 > > [Seismograms] [Notification Message] [Solution Output] [Phase Listing] > [Return to TOP] > > [BACK TO EARTHQUAKE LIST] > > ---------------------------------------------------------------------- > [Image] Return to USGS homepage _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Stephen Caruso Subject: Re: ISAIAH AUTOMATIC DATA SUMMARY FOR EVENT ID=9038429 Date: Sun, 4 Jan 1998 19:54:07 -0500 (EST) Marnie, I don't know if anybody else has a problem with your message (if they don't then ignore this one)but there is alot of html language aboard. I have noticed an html option in the software but if that's what you intended I'll have to load it into a browser off this 8088. Thanks for the bandwidth. STEPHEN CARUSO CET KB8UGH "Coincidence is a shortsighted mental delusion" _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Stephen Caruso Subject: Re: ISAIAH AUTOMATIC DATA SUMMARY FOR EVENT ID=9038429 Date: Sun, 4 Jan 1998 20:20:39 -0500 (EST) Don't get me wrong, I am enthused w/every PSN message. I just thought you weren't aware of what was coming across the net. Thanks for posting.:^) STEPHEN CARUSO CET KB8UGH "Coincidence is a shortsighted mental delusion" _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: meredith lamb Subject: Trading Post? Date: Sun, 04 Jan 1998 20:19:39 -0700 Hi everyone, This is tentative in thought...Is anyone interested in trading whatever for whatever?? I know for myself... I have a surplus of old stuff I'll likely never get around to using. Expect there is afew out there in the same surplus condition, who would treasure someone else's endless storage goodies. This avocation cost can be considerable over a period of time and a swap may bring a faster and cheaper solution than commercial approaches. Guess it would be fun too. I'am sure that an endless email approach is not desired over the PSN machine. Perhaps, for those interested they could privately communicate outside PSN per their own individual email. It should be possible to make it a swap only....no cash involved....except for postage costs. Anyway....being as this is just a thought...what do you think? Rules? Limitations? Gone Fishing in this PSN pond.........?? Thanks, Meredith Lamb _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Marnie Gannon Subject: Re: ISAIAH AUTOMATIC DATA SUMMARY FOR EVENT ID=9038429 Date: Sun, 04 Jan 1998 21:23:46 -0700 Stephen Caruso wrote: > > Don't get me wrong, I am enthused w/every PSN message. I just thought you > weren't aware of what was coming across the net. Thanks for posting.:^) Sorry, you guys, for some reason the seismogram didn't send on the page link..What it was..not what is showing in your post, was a series of tremors on one 60 second plot..I think it showed about 4 8-10 second events, separated by smaller periods with no signal at all..each of the tremors seemed to have its own p wave, not sure about s.. Darn, wish I could show it to you. The entire quake has been deleted now... so I can't send it as a link or anything. Still about 70 or so deleted links on the page for Parkfield and San Luis Obispo quakes...I'm assuming these are bad locations for Mammoth quakes... The ISAIAH site is great..I refer to it often, just lately alot of odd links, deleted, etc.. You hadtohavebeenthere I guess! Sorry about the posting snafu.. Marnie _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: kathy mortensen Subject: DATAQ DI-150RS Date: Sun, 04 Jan 1998 21:01:09 -0700 O.K. I just found the PSN mailing list about 3 weeks ago and have been glued to my email. I was intriged with Sean Thomas Idea of using the Radio Shack dvm as a data recorder. I've been looking for an economical way to record my seimograph signals. When I checked with Radio Shack I discovered their data logger. I ordered it and received it on the 9th working day (UPS) the day before new years eve. You know what I've been doing ---no partying--- !!! I did learn a lot about com ports and IRQs!! With a mouse on com-1 IRQ-4 and a modem on com-2 IRQ-3, both activated in windows, I was stuck!! I tried ever combination of com amd IRQs --- with lockup,lockup,lockup#!%@ I down loaded the sample qbasic program from the dataq web site and finally got it to respond --- sometimes --- . It sometimes missed the respond signal and would --guess what-- yes, lockup#%$#@! Next I decided to disable the modem in windows -- we won't go into that story. The easy way turned out to be to load a short version of windows into a separate directory ---fun,fun,fun%$#@! loaded the dataq software --- guess what -- does not respond!!! FINALLY to the point of this story!! I downloaded the latest software from their web site (as they put it - if you have problems) daaa!! YES,YES,YES --- it works!!! The best data logger I ever had --- of course it is also the worst -- it's the only one!!! I have nothing to compare it to!!! At this point I suspect that I am not compatible with anyone!! At last I can record waveforms. I was on line when the loyalty set off my alarm but I was in the standby mode %$#@#$!!!! but I did catch the end of it and the two mammoths at approx. 4:30 A.M. A long story but hopefully helpful to anyone considering getting a DATAQ. Stephen K. Mortensen here after SKM email mortskm@....... Pilot Hill, Calif. USA _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: RADIOTEL Subject: Re: Trading Post? Date: Mon, 5 Jan 1998 00:41:37 EST MEREDITH LAMB Your trading post idea is great. I say lets go for it. Jim Allen Cerritos, California _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Norman Davis WB6SHI Subject: Re: DATAQ DI-150RS Date: Sun, 04 Jan 1998 22:44:23 I was intriged with Sean Thomas Idea of using the Radio Shack >dvm as a data >recorder. I have been using the rs dvm for loging for a while now and find the sapling rate to slow. 1 sec but it does work and is great for trouble shooting and designing amps and filters. I and mike d have been thinking of the dataq modual for this purpose and intersted in your post. > I was on line when the loyalty set off my alarm but I was >in the standby >mode %$#@#$!!!! but I did catch the end of it and the two mammoths at >approx. 4:30 A.M. What is loyalty?? >A long story but hopefully helpful to anyone considering getting a >DATAQ. I could use it for other stuff like radio astomomy and weather data but think I will put any further money into a good adc board as then I can use a program like emon or sdr. Norman Davis WB6SHI Email normd@............. Shingle Springs, Ca, USA it ain't local... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: PSN records for M. Antolik - Map / MPEG viewers Date: Sun, 04 Jan 1998 23:03:34 -0800 Greetings, Does anyone know of a MPEG viewer that can display the files at the link below. All of the Win95/NT versions I can find on the Net either won't display the pictures correctly or need to be registered to display the large files. While I'm at it... I'm also looking for a good commercial street map program that can be used to display the location of local or regional events. A long time ago I had a Windows 3.1 program called LocalExpert. It was limited in what it could do but was OK for locating local events. It would allow you to draw circles of X diameter so one could plot the event location based on the P and S wave distance from several stations. Unfortunately I lost that program a while back when I had a hard disk crash. I now do regular backups... I now have a program called Precision Mapping 2.0. Its not very good. It only displays distance in miles, no km, and drawing of a circle is real flaky. So if anyone can suggest a good MPEG view and / or map program please let me know. Regards, Larry Cochrane Redwood City, PSN At 02:53 PM 1/2/98 -0700, Edward Cranswick wrote: >PSN members in the San Francisco Bay Area- > 3-dimensional, finite-difference models of seismic wave propagation and >site response in the San Francisco Bay Area created by members of the >Seismic Station at UCB can be seen: > >http://www.seismo.berkeley.edu/seismo/events_of_interest/3dmod/3dmod.html > >-Edward _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: kathy mortensen Subject: Re: DATAQ DI-150RS Date: Sun, 04 Jan 1998 23:35:29 -0700 What is loyalty?? > LOYALTY ISLANDS REGION was the reference that USGS gave for a 7.0 earthquake N.E. of astralia -- 22.17S, 170.51E Jan 4 06:11:50 1998 GMT About 6,100 miles from here! > Norman Davis WB6SHI > Email normd@............. > Shingle Springs, Ca, USA it ain't local... > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "frank murray" Subject: RE: PSN records for M. Antolik - Map / MPEG viewers Date: Mon, 5 Jan 1998 00:06:12 -0800 > -----Original Message----- > From: Larry Cochrane [mailto:cochrane@............... > Sent: Sunday, January 04, 1998 11:04 PM > To: PSN-L Mailing List > Subject: Re: PSN records for M. Antolik - Map / MPEG viewers > > > Greetings, > > Does anyone know of a MPEG viewer that can display the files at the link > below. All of the Win95/NT versions I can find on the Net either won't > display the pictures correctly or need to be registered to display the > large files. > i tried the ones for the hayward fault and found that the smaller two (about ..2 mbyte and .5 mbyte) would run under ie4, but not the larger one...i suspect that updating my version of RUNDLL32 should do it...the updates are usually available at the ms site...i'll let you know if that works...and thanks for the cue to the site...cool movies... frank _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jim Hannon Subject: Re: PSN records for M. Antolik - Map / MPEG viewers Date: Mon, 05 Jan 1998 05:55:02 -0600 Larry Cochrane wrote: > While I'm at it... I'm also looking for a good commercial street map > program that can be used to display the location of local or regional > events. A long time ago I had a Windows 3.1 program called LocalExpert. It > was limited in what it could do but was OK for locating local events. It > would allow you to draw circles of X diameter so one could plot the event > location based on the P and S wave distance from several stations. > Unfortunately I lost that program a while back when I had a hard disk > crash. I now do regular backups... I now have a program called Precision > Mapping 2.0. Its not very good. It only displays distance in miles, no km, > and drawing of a circle is real flaky. > > So if anyone can suggest a good MPEG view and / or map program please let > me know. > > Regards, > Larry Cochrane > Redwood City, PSN Larry, We have been using software and data from DeLorme Mapping Co. at work for our GPS tracking system. I can find out more about how well it works today from the guys that are actually using it. -- Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N 91,39.26W WB0TXL _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "frank murray" Subject: anything at 12:50 UTC??... Date: Mon, 5 Jan 1998 05:15:25 -0800 did anyone pick up something just prior to 12:50 UTC on 1/5/98??... frank _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ralvarez@........ (Raul Alvarez) Subject: Re: Trading Post? Date: Mon, 5 Jan 1998 06:34:06 -0700 (MST) Greetings! Great idea!! I sure have a lot of junk, er, treasure, I can swap. Why not also post your needed items? Raul >Hi everyone, > >This is tentative in thought...Is anyone interested in trading >whatever for whatever?? I know for myself... I have a >surplus of old stuff I'll likely never get around to using. > >Expect there is afew out there in the same surplus condition, >who would treasure someone else's endless storage goodies. > >This avocation cost can be considerable over a period of >time and a swap may bring a faster and cheaper solution >than commercial approaches. Guess it would be fun too. > >I'am sure that an endless email approach is not desired over >the PSN machine. Perhaps, for those interested they >could privately communicate outside PSN per their own >individual email. It should be possible to make it a swap >only....no cash involved....except for postage costs. > >Anyway....being as this is just a thought...what do you >think? Rules? Limitations? Gone Fishing in this PSN >pond.........?? > >Thanks, Meredith Lamb > > > > > > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~ ~ ~ "My dreams are the seeds of my reality, ~ ~ nurtured in the womb of my soul" ~ ~ RJA, 1985 ~ ~ ~ ~ ~ ~ Raul J. Alvarez ~ ~ Bellvue, Colorado ~ ~ e-mail ralvarez@........ ~ ~ homepage www.frii.com/~ralvarez ~ ~ "The Renaissance Experimenter" ~ ~ experimenter in: ~ ~ Radio and Optical Astronomy, Seismology, Weather, ~ ~ Computers, Instrumentation and Neat Stuff! ~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Mike Lozano Subject: Re:Trading Post! Date: Mon, 05 Jan 1998 08:54:54 -0600 Hi guys! Trading post sounds like a great idea! Why don't I kick things off with two offerings: 1 ea. FastVac DV-85/DV-142 Series Deep Vacuum Pump BRAND NEW - NEVER EVEN PLUGGED IN! with spare Wankel-type cylinder replacement kit (still in box), and 1 Qt. of oil (still sealed). Purchased for around $400 for a project that never got off the ground. Great for micro-barometry experimenters! 2 ea. DRSI Micro Data Link Controllers (packet radio system) Licensed on commercial itinerant frequency in the 460 MHz band (5 watt transmitter and cut-to-frequency rubber duck antennas on BNC connectors. This system uses commercial packet standard, and is not easily compatible with amateur packet. Used, but in MINT condition. Purchased for around $1500. Set up your own remote seismic station! Mike Lozano, N0BDF mikel@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: watson@................ (Charles Watson) Subject: Re: ISAIAH AUTOMATIC DATA SUMMARY FOR EVENT ID=9038429 Date: Mon, 05 Jan 1998 07:35:27 -0700 Stephen Caruso wrote: > > Don't get me wrong, I am enthused w/every PSN message. I just thought you > weren't aware of what was coming across the net. Thanks for posting.:^ I can understand your frustration, Steve. It has been my experience that different web browsers interpret web sites differently and it is the same for e-mail readers as well. When Marnie attaches the html document, many modern e-mail readers, like Netscape, Explorer, Claris, etc., can interpret the html language and format the message in a full html document with font enhancements, links and graphics. Quite a wonderful invention, really! I used it extensively when publishing Seismo-Watch Earthquake Alert Bulletins via e-mail. However, the draw back is many people do not use these modern e-mail readers and it can be a bother when all they see is a bunch of html scripting. They really don't know what they are missing and it can be frustrating to get all the gibberish html. I have found it is best when passing information from other web sites to simply provide the html link and if people are really interested, they can go to the web site and see it for themselves. Cheers! -- ---/---- Charles P. Watson, Consulting Geologist Advanced Geologic Exploration Seismo-Watch / Earthquake Information Services Voice: 702-852-0992 / Fax: 702-852-3226 Office Location: 39.43N 119.71W mailto:watson@................ http://www.seismo-watch.com _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Norman Davis WB6SHI Subject: Re: PSN records for M. Antolik - Map / MPEG viewers Date: Mon, 05 Jan 1998 07:31:27 >While I'm at it... I'm also looking for a good commercial street map >program that can be used to display the location of local or regional >events. A long time ago I had a Windows 3.1 program called LocalExpert. It >was limited in what it could do but was OK for locating local events. It >would allow you to draw circles of X diameter so one could plot the event >location based on the P and S wave distance from several stations. >Unfortunately I lost that program a while back when I had a hard disk >crash. I now do regular backups... I now have a program called Precision >Mapping 2.0. Its not very good. It only displays distance in miles, no km, I have the newer version 3.0 it and it seems to me that it will do km and the circles look good, IMHO. Norm Norman Davis WB6SHI Email normd@............. Shingle Springs, Ca, USA it ain't local... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: watson@................ (Charles Watson) Subject: Re: Trading Post! Date: Mon, 05 Jan 1998 07:57:37 -0700 Hey this is a great idea! Maybe a web page could be set up at the PSN web site that could deal with these "treasures". Call it the "PSN Trading Post". -- ---/---- Charles P. Watson, Consulting Geologist Advanced Geologic Exploration Seismo-Watch / Earthquake Information Services Voice: 702-852-0992 / Fax: 702-852-3226 Office Location: 39.43N 119.71W mailto:watson@................ http://www.seismo-watch.com _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: PSN records for M. Antolik - Map / MPEG viewers Date: Mon, 05 Jan 1998 09:44:12 -0700 Larry- I think that I am using a plugin from Intervu, http://www.intervu.net/ though I am somewhat confused about what is going on when I try to track down the details of my instalation of Netscape Navigator Gold ver 3.01. -Edward Larry Cochrane wrote: > > Greetings, > > Does anyone know of a MPEG viewer that can display the files at the link > below. All of the Win95/NT versions I can find on the Net either won't > display the pictures correctly or need to be registered to display the > large files. -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: dean sevold Subject: Fwd: Meteorite News Date: Mon, 05 Jan 98 08:49:27 PST Date: Sun, 04 Jan 98 16:11:05 PST From: Klaus Georg Hansen To: dean sevold Subject: Meteorite News Dear Dean Last news from Greenland (KNR): Today (4th) 10.000 km2 has been overflewn by an airplane with the special radar. On the plane were a crew of 11 specialists. The area overflewn is between Groennedal to the south and Nuuk to the north. Radar operator Soeren Madsen Danish Technical University told KNR they saw nothing from the plane that with certainty was a meteorite, but something might be interpreted as a strike area. Now all the data from the radar must be analysed on computers in Denmark before anytning new can be said. These analysis might last for a week or so. Klaus Georg Hansen _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Marnie Gannon Subject: Re: PSN records for M. Antolik - Map / MPEG viewers Date: Mon, 05 Jan 1998 10:04:31 -0700 Edward Cranswick wrote: > > Larry- > I think that I am using a plugin from Intervu, > > http://www.intervu.net/ Edward, Just went over and looked at the site. Do you find it true that it speeds graphics downloads by two or three times? Marnie _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ERICH777 Subject: Event So CA Date: Mon, 5 Jan 1998 13:20:31 EST To : psn-l@............. Subject: Time: Date: Jan 5 approx 10 :14 Station Location 33,51.00N 118,8.33W Remarks; P to S 24 miles away A n George Erich ~~~~~~~|~~~~~~~~~~/~~~~~ Seismic Exploration Consulting Services '' ' ' ' ' ' ' 'O' " ' ' ' ' '` ' ' ' ' /' ' ' ' ' ' ' P. O. Box 2011 ` ` ` ` ` ` ` \ ` ` `` ` ' '` ` / ` ` ` ` ` ` Norwalk, CA 90651-2011 USA . . . . . . . . \ . . . . . . / . . . . . . - - - - - - - - -\ - - - - -/ - - - - - - - Telephone (562) 868-6013 : : : : : : : : : \ : :' ::/ : : : : : : : e-mail GeE777@....... \ / ' ' ' ' ' ' ' ' ' ' ' ' '.\ ' / " " " " " " " Psalms 85:11 Truth shall spring out of the earth; . . . .. ___V___________ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ERICH777 Subject: Re; Geophone Date: Mon, 5 Jan 1998 13:12:05 EST Hi all Date: 98-01-03 18:49:16 EST normd@............. (Norman Davis WB6SHI) writes; << I just got a copy of rtclark cataloge. There are two types of geophones. One is called shearwave and the other nothing. I asume the lower freq the better.>> I have used the GSC-11D geophone in work with exploration seismology. Don't worry about soldering, I'ts made for that. The notrhing is a vertical phone. I suggest RT Ckark used seismic equipment catalog at ( rtclark@........... ) for inexpensive equipment. Remember, most of their stuff is for seismic exploration and they record higher frequency seismic signals. A n George Erich ~~~~~~~|~~~~~~~~~~/~~~~~ Seismic Exploration Consulting Services '' ' ' ' ' ' ' 'O' " ' ' ' ' '` ' ' ' ' /' ' ' ' ' ' ' P. O. Box 2011 ` ` ` ` ` ` ` \ ` ` `` ` ' '` ` / ` ` ` ` ` ` Norwalk, CA 90651-2011 USA . . . . . . . . \ . . . . . . / . . . . . . - - - - - - - - -\ - - - - -/ - - - - - - - Telephone (562) 868-6013 : : : : : : : : : \ : :' ::/ : : : : : : : e-mail GeE777@....... \ / e-mail ERICH777@....... ' ' ' ' ' ' ' ' ' ' ' ' '.\ ' / " " " " " " " Psalms 85:11 Truth shall spring out of the earth; . . . .. ___V___________ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "frank murray" Subject: RE: Event So CA Date: Mon, 5 Jan 1998 10:52:04 -0800 this from usgs: 98/01/05 18:14:06 33.94N 117.71W 7.8 4.3Ml SOUTHERN CALIFORNIA > -----Original Message----- > From: ERICH777 [mailto:ERICH777@........ > Sent: Monday, January 05, 1998 10:21 AM > To: psn-l@............. > Subject: Event So CA > > > To : > psn-l@............. > Subject: > Time: > > Date: Jan 5 approx 10 :14 > > > Station Location > 33,51.00N > 118,8.33W > > Remarks; > P to S 24 miles away > > > A n > George Erich > ~~~~~~~|~~~~~~~~~~/~~~~~ > Seismic Exploration Consulting Services '' ' ' ' ' ' ' 'O' " ' ' ' ' '` > ' ' ' ' /' ' ' ' ' ' ' > P. O. Box 2011 ` ` ` ` ` ` ` \ ` ` > `` ` ' '` ` / ` ` ` ` ` ` > Norwalk, CA 90651-2011 USA . . . . . . . . \ . . . . .. . > / . . . . . . > - - - - - - > - - -\ - - - - -/ - - - - - - - > Telephone (562) 868-6013 : : : : : : : : : \ : :' > ::/ : : : : : : : > e-mail GeE777@....... \ / > ' ' ' ' ' ' > ' ' ' ' ' ' '.\ ' / " " " " " " " > Psalms 85:11 Truth shall spring out of the earth; . . . .. ___V___________ > > > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: bob@................. (Bob Hammond (USGS-AVO Geophysicist)) Subject: Re: Geophone Date: Mon, 5 Jan 1998 09:51:54 -0900 Norman Davis, et al: I use a Mark Products L4 geophone which is sold by the RT Clark, Co. I suggest using this geophone as a short-period vertical sensor for amateur seismographs because it a 1-Hz seismometer, has good response, and is used by virtually all of the university and government seismograph networks in the US. Keep in mind that geophones normally used in oil exploration are 2 Hz geophones and are not as good for monitoring regional and local earthquakes as a 1 Hz instrument. The L4 comes with a calibration coil and is marked as a L4-C. You don't need the cal coil. regards, Bob Hammond APSN Fairbanks (- 43F this morning) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: PSN records for M. Antolik - Map / MPEG viewers Date: Mon, 05 Jan 1998 12:16:37 -0700 Marnie- I don't know, i.e., I have not done any benchmark tests; against what? -Edward Marnie Gannon wrote: > > Edward Cranswick wrote: > > > > Larry- > > I think that I am using a plugin from Intervu, > > > > http://www.intervu.net/ > > Edward, > > Just went over and looked at the site. Do you find it true that it > speeds graphics downloads by two or three times? > > Marnie > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Stephen Paul Subject: Re: MA EVENT Date: Mon, 05 Jan 1998 10:36:03 -0800 Karl Cunningham wrote: > Stephen -- > > I just uploaded my event file for your felt earthquake... > > 98/01/04 09:11:45 34.20N 118.62W 0.0 3.2ML 1 mi W of CANOGA PARK > > Karl Cunningham > La Mesa, CA. > PSN Station #40 > karlc@....... > > At 02:13 AM 1/4/98 -0800, Stephen Paul wrote: > > Larry, did you or nyone else pick up something around 1-1:30 PST? I felt a > >fairly muted but strong tremor in the Sherman Oaks area of So. CA this > >morning, and went online a bit later to see if there was any news, and lo and > >behold, you magic Indians had your ears to the ground! Not surprising, I was > >just wondering if this might be related... > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L Thanks Karl... I'm really beginning to suspect the interrelatedness of these events all over the world, and most especially on the opposite sides of the rim. We had a real shaker again this morning at about 02:20 UTC. Preliminary reports I've seen say it was a 4.1 centered in Chino, CA... I suspect it isn't the end... my house felt like a 747 landing for close to 30-45 seconds! Apparently this one was widely felt... There are so many fractures down here that sometimes it's hard to tell just what is happening, i.e. is it a big one far off or a small one close by? A lot depends on how the P wave feels. The sharper the jolt, the closer it usually is. But I guess the length of duration of the S is what causes the mondo damage. And Italy seems to be still having more than its share of woes. Did you happen to map this morning's event? Appreciate the reply. Thanks. -- Stephen :^) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Stephen Paul Subject: Re: PSN records for M. Antolik - Map / MPEG viewers Date: Mon, 05 Jan 1998 11:11:27 -0800 Larry Cochrane wrote: > Greetings, > > Does anyone know of a MPEG viewer that can display the files at the link > below. All of the Win95/NT versions I can find on the Net either won't > display the pictures correctly or need to be registered to display the > large files. > > While I'm at it... I'm also looking for a good commercial street map > program that can be used to display the location of local or regional > events. A long time ago I had a Windows 3.1 program called LocalExpert. It > was limited in what it could do but was OK for locating local events. It > would allow you to draw circles of X diameter so one could plot the event > location based on the P and S wave distance from several stations. > Unfortunately I lost that program a while back when I had a hard disk > crash. I now do regular backups... I now have a program called Precision > Mapping 2.0. Its not very good. It only displays distance in miles, no km, > and drawing of a circle is real flaky. > > So if anyone can suggest a good MPEG view and / or map program please let > me know. > > Regards, > Larry Cochrane > Redwood City, PSN > > At 02:53 PM 1/2/98 -0700, Edward Cranswick wrote: > >PSN members in the San Francisco Bay Area- > > 3-dimensional, finite-difference models of seismic wave propagation and > >site response in the San Francisco Bay Area created by members of the > >Seismic Station at UCB can be seen: > > > >http://www.seismo.berkeley.edu/seismo/events_of_interest/3dmod/3dmod.html > > > >-Edward > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L Larry, do you know what type or layer MPEG it is? If it's MJPEG this could be the problem, and I do have solutions for most everything viewable... might it be in DVD format? That could cause difficulty too. I have a Post setup in my shop and can steer you to a solution most likely. I'll pop over the link also and see what I can find out and hopefully let you know something within a few days. Keep your fingers crossed... I'm also a computer dealer on the side, and if you can find out who wrote or manufactured the map program, I will check through my distributors for what you need and get it to you wholesale... Let me know if I can help. -- Stephen :^) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Stephen Paul Subject: Re: PSN records for M. Antolik - Map / MPEG viewers Date: Mon, 05 Jan 1998 11:40:19 -0800 Larry Cochrane wrote: > Greetings, > > Does anyone know of a MPEG viewer that can display the files at the link > below. All of the Win95/NT versions I can find on the Net either won't > display the pictures correctly or need to be registered to display the > large files. > > While I'm at it... I'm also looking for a good commercial street map > program that can be used to display the location of local or regional > events. A long time ago I had a Windows 3.1 program called LocalExpert. It > was limited in what it could do but was OK for locating local events. It > would allow you to draw circles of X diameter so one could plot the event > location based on the P and S wave distance from several stations. > Unfortunately I lost that program a while back when I had a hard disk > crash. I now do regular backups... I now have a program called Precision > Mapping 2.0. Its not very good. It only displays distance in miles, no km, > and drawing of a circle is real flaky. > > So if anyone can suggest a good MPEG view and / or map program please let > me know. > > Regards, > Larry Cochrane > Redwood City, PSN > > At 02:53 PM 1/2/98 -0700, Edward Cranswick wrote: > >PSN members in the San Francisco Bay Area- > > 3-dimensional, finite-difference models of seismic wave propagation and > >site response in the San Francisco Bay Area created by members of the > >Seismic Station at UCB can be seen: > > > >http://www.seismo.berkeley.edu/seismo/events_of_interest/3dmod/3dmod.html > > > >-Edward > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L Larry, I successfully played the movie with the built in Media Player in Win 95... Haven't checked the 32 bit ver. in NT yet, but in 95 (Build 950a-IOW Sevice pack 1 installed for 95, available from the MS site) it ran fine. I do have Mpeg decoders built in all over the place, but try that and let me know if it plays. If not, I'll check my System.ini and find out what module is being used to play it besides Rundll, and see if I can send you a copy. Most of my MPEG stuff is distributable. -- Stephen :^) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: MA EVENT Date: Mon, 05 Jan 1998 12:46:29 -0700 Stephen- You appear to be in a very sensitive site for picking up events -- and this makes sense in terms of the concentrated pattern of damage to Sherman Oaks by the Northridge Earthquake. What is your address? -Edward Stephen Paul wrote: > > frank murray wrote: > > > if everybody could pop their times and locations into their posts, we could > > all see the pattern of the waves... > > > > > -----Original Message----- > > > From: Tom Frey [mailto:tfrey@............ > > > Sent: Saturday, January 03, 1998 10:45 PM > > > To: PSN-L Mailing List > > > Subject: Re: MA EVENT > > > > > > > > > Same Here!!!! > > > > > > > > > > > Tom, > > As I mentioned to Larry, I didn't get the time, but my house really swayed down > here in Sherman Oaks, San Fernando Valley area of So. CA > -- > Stephen Paul :^) > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: watson@................ (Charles Watson) Subject: Global M5+ Activity - record tying sequence Date: Mon, 05 Jan 1998 13:17:21 -0700 As I was preparing this week's Seismo-Watch Global Earthquake Report for December 21-27, 1997, I noticed there have been 8 consecutive weeks of 20+ earthquakes registering M5 or stronger. (Week: Sunday through Satruday; Time: GMT; Source: NEIC QED and PDE files) Sustained activity at this level is uncommon happenning only 3 prior times in the last 5 years (twice in 1995 and from Feb - Apr earlier in 1997). I have not looked in the PDE catalogs prior to 1992, but does anyone know how often this has occurred before this and if there have ever been 9 consecutive weeks of 20+ earthquakes registering M5 or stronger? -- ---/---- Charles P. Watson, Consulting Geologist Advanced Geologic Exploration Seismo-Watch / Earthquake Information Services Voice: 702-852-0992 / Fax: 702-852-3226 Office Location: 39.43N 119.71W mailto:watson@................ http://www.seismo-watch.com _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Walt Williams" Subject: Re:Trading Post! & Suggestions Date: Mon, 5 Jan 1998 14:12:40 +0000 Hello PSN-L, The idea of a 'Trading Post' is an interesting idea. In the tradition of technical reflectors, items for swap / sale are typically listed seperate to avoid clogging the 'data' channel. Perhaps the PSN-L host could be asked nicely to provide a separate list or web space? If not, and depending upon traffic (as I am busy these days), I will offer some web page space for PSN-L list members to post their offerings / wants. I pose a question: fellow PSN-Ls, do we really want 'spam' co-mingled with normal dialog of the list? Best Regards, Walt Williams, 98.01.05 dfheli@.............. http://www.pacificnet.net/~dfheli Canoga Park, (LA suburb), California USA ===================================================== ------- Forwarded Message Follows ------- Date: Mon, 05 Jan 1998 08:54:54 -0600 From: Mike Lozano Reply-to: PSN-L Mailing List Organization: Applied Sciences, Ltd. To: PSN-L Mailing List Subject: Re:Trading Post! Hi guys! Trading post sounds like a great idea! Why don't I kick things off with two offerings: 1 ea. FastVac DV-85/DV-142 Series Deep Vacuum Pump BRAND NEW - NEVER EVEN PLUGGED IN! with spare Wankel-type cylinder replacement kit (still in box), and 1 Qt. of oil (still sealed). Purchased for around $400 for a project that never got off the ground. Great for micro-barometry experimenters! 2 ea. DRSI Micro Data Link Controllers (packet radio system) Licensed on commercial itinerant frequency in the 460 MHz band (5 watt transmitter and cut-to-frequency rubber duck antennas on BNC connectors. This system uses commercial packet standard, and is not easily compatible with amateur packet. Used, but in MINT condition. Purchased for around $1500. Set up your own remote seismic station! Mike Lozano, N0BDF mikel@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: lahr@.................. Subject: exploration geophones Date: Mon, 5 Jan 1998 15:44:09 -0700 (MST) On my web site I give some information on obtaining a free exploration geophone from Arlen Juels of Seistex `86 Inc. These are used phones that would probably work fine for local earthquake monitoring. http://www.giseis.alaska.edu/Input/lahr/web.sites.html#GEOPHONES JCLahr ################################## John C. Lahr ################################# Seismologist ################################ U.S. Geological Survey ############################### Geologic Hazards Team, MS966 ############################## PO Box 25046 #############################/############################## ############################/############################### Denver, Colorado 80225-0046 ################################ Phone: (303) 273-8596 ################################## Fax: (303) 273-8600 ################################### lahr@........ ##################################### http://www.aeic.alaska.edu/lahr _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Marnie Gannon Subject: LA peak velocties/acceleration Date: Mon, 05 Jan 1998 16:34:00 -0700 Don't know if you all know about this page: http://www-socal.wr.usgs.gov/pga.html It's a prototype which has computer generated contour maps of 1. Peak Velocity 2. Peak Acceleration 3. Focal Mechanism and 4. Individual station info for Southern California. The Chino earthquake is up now. Most significant local EQs will show up in about 5 minutes.. Marnie _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: evans@.................... (John Evans) Subject: ADXL-05 info Date: Mon, 5 Jan 98 16:00:00 PST Edward, Please post the following info for the PSN folks. It's recent price and availability for the ADXL05 accel (a fairly noisy but interesting device good for demos at least). Some may be interested: Distributors: 800-463-9275 Subject: Re: DATAQ DI-150RS Date: Mon, 5 Jan 1998 16:45:12 -0800 I'm pretty new to all this monitoring, and been thinking about the DATAQ logger. But I don't have the COM1 conflicts that you do. Since you dint specify what computer you are using, is it possible your motherboard has a PS/2 connector on it? If so, you either buy a PS/2 mouse or get an adapter cable to convert your RS-232 mouse to a PS/2 mouse and free up that RS-232 port! BTW, the RS232 mice are the slowest ones and that is why so many folks use the PS/2 connector. Now, the bit question: What device is the input to your DATAQ card? and is it the DATAQ software that gives you the "alarm" you talk about? Dennis Eckert KB7ST (Amateur Radio Operator) Flies Standard Cirrus sailplane (SV) In Western & Eastern Washington ICQ 4324132 -----Original Message----- From: kathy mortensen To: psn-l@............. Date: Sunday, January 04, 1998 9:03 PM Subject: DATAQ DI-150RS >O.K. I just found the PSN mailing list about 3 weeks ago and have been >glued to my >email. I was intriged with Sean Thomas Idea of using the Radio Shack >dvm as a data >recorder. I've been looking for an economical way to record my >seimograph signals. >When I checked with Radio Shack I discovered their data logger. I >ordered it and >received it on the 9th working day (UPS) the day before new years eve. >You know what >I've been doing ---no partying--- !!! I did learn a lot about com >ports and IRQs!! >With a mouse on com-1 IRQ-4 and a modem on com-2 IRQ-3, both activated >in windows, I >was stuck!! I tried ever combination of com amd IRQs --- with >lockup,lockup,lockup#!%@ >I down loaded the sample qbasic program from the dataq web site and >finally got it to >respond --- sometimes --- . It sometimes missed the respond signal and >would --guess >what-- yes, lockup#%$#@! Next I decided to disable the modem in >windows -- we won't >go into that story. The easy way turned out to be to load a short >version of windows >into a separate directory ---fun,fun,fun%$#@! loaded the dataq >software --- guess >what -- does not respond!!! FINALLY to the point of this story!! I >downloaded >the latest software from their web site (as they put it - if you have >problems) daaa!! > YES,YES,YES --- it works!!! The best data logger I ever had --- >of course it >is also the worst -- it's the only one!!! I have nothing to compare >it to!!! >At this point I suspect that I am not compatible with anyone!! At >last I can record >waveforms. I was on line when the loyalty set off my alarm but I was >in the standby >mode %$#@#$!!!! but I did catch the end of it and the two mammoths at >approx. 4:30 A.M. >A long story but hopefully helpful to anyone considering getting a >DATAQ. > >Stephen K. Mortensen here after SKM >email mortskm@....... >Pilot Hill, Calif. USA > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: watson@................ (Charles Watson) Subject: Re: LA peak velocties/acceleration Date: Mon, 05 Jan 1998 17:00:33 -0700 Marnie Gannon wrote: > > Don't know if you all know about this page: > > http://www-socal.wr.usgs.gov/pga.html > > It's a prototype which has computer generated contour maps of 1. Peak > Velocity 2. Peak Acceleration 3. Focal Mechanism and 4. Individual > station infofor Southern California. The Chino earthquake is up now. > Most significant local EQs will show up in about 5 minutes.. Thanks for redirecting my attention to the site. My felt reports from the region suggest the acceleration map is pretty good. I got sharply felt reports from Chino, Sierra Madra and San Gabriel Valley (to the NNW) as well as from the Riverside region (to the SE), but every one else did not feel it as sharply. -- interesting. -- ---/---- Charles P. Watson, Consulting Geologist Advanced Geologic Exploration Seismo-Watch / Earthquake Information Services Voice: 702-852-0992 / Fax: 702-852-3226 Office Location: 39.43N 119.71W mailto:watson@................ http://www.seismo-watch.com _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Marnie Gannon Subject: Re: LA peak velocties/acceleration Date: Mon, 05 Jan 1998 18:21:04 -0700 Charles Watson wrote: > > > Thanks for redirecting my attention to the site. My felt reports from > the region suggest the acceleration map is pretty good. I got sharply > felt reports from Chino, Sierra Madra and San Gabriel Valley (to the > NNW) as well as from the Riverside region (to the SE), but every one > else did not feel it as sharply. -- interesting. Same here Charles, Friends and news reports say it was a sharp, 3-4 second, jolting quake. I didn't notice the first time that when you click on the triangles the ind.station info comes up..Check out Seal Beach! Marnie _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: TESMECO Subject: Re: Trading Post? Date: Mon, 5 Jan 1998 20:48:49 EST good idea _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Stephen Paul Subject: Re: MA EVENT Date: Mon, 05 Jan 1998 18:04:37 -0800 Edward Cranswick wrote: > Stephen- > You appear to be in a very sensitive site for picking up events -- and > this makes sense in terms of the concentrated pattern of damage to > Sherman Oaks by the Northridge Earthquake. What is your address? > -Edward > > Stephen Paul wrote: > > > > frank murray wrote: > > > > > if everybody could pop their times and locations into their posts, we could > > > all see the pattern of the waves... > > > > > > > -----Original Message----- > > > > From: Tom Frey [mailto:tfrey@............ > > > > Sent: Saturday, January 03, 1998 10:45 PM > > > > To: PSN-L Mailing List > > > > Subject: Re: MA EVENT > > > > > > > > > > > > Same Here!!!! > > > > > > > > > > > > > > > > Tom, > > > > As I mentioned to Larry, I didn't get the time, but my house really swayed down > > here in Sherman Oaks, San Fernando Valley area of So. CA > > -- > > Stephen Paul :^) > > > > _____________________________________________________________________ > > > > Public Seismic Network Mailing List (PSN-L) > > > > To leave this list email listserver@............. with the body of the > > message: leave PSN-L > > -- > Edward Cranswick Tel: 303-273-8609 > US Geological Survey, MS 966 Fax: 303-273-8600 > PO Box 25046, Federal Center cranswick@........ > Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L Edward, I am in the hills about 1 block E. of Woodman, and a mile or so south, and I would guess at an elevation of roughly 800-1200 ft. above the boulevard. Though many felt the event was 3-4 seconds, up here I definitely felt motion for 30-45 seconds. And you are so right. I can feel even the slightest tremors up here, which is a characteristic of being in the hills, mostly bedrock I believe, though more damage resulted here than in Studio City hills, my former residence for 10 years... I guess it's like being at the end of a stick where you can really fell the motion. What do you think of the 'ringing bell' hypothesis put forward some years ago? I tend to believe it... I read aboout it in an article in Scientific American some 6-7 years ago. Are you aware of it? -- Stephen :^) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: LA peak velocties/acceleration Date: Mon, 05 Jan 1998 21:43:34 -0700 Charlie & Marnie- Where are you getting your felt reports from? -Edward Marnie Gannon wrote: > > Charles Watson wrote: > > > > > Thanks for redirecting my attention to the site. My felt reports from > > the region suggest the acceleration map is pretty good. I got sharply > > felt reports from Chino, Sierra Madra and San Gabriel Valley (to the > > NNW) as well as from the Riverside region (to the SE), but every one > > else did not feel it as sharply. -- interesting. > > Same here Charles, > > Friends and news reports say it was a sharp, 3-4 second, jolting quake. > I didn't notice the first time that when you click on the triangles the > ind.station info comes up..Check out Seal Beach! > > Marnie > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ERICH777 Subject: Re: Geophone Date: Mon, 5 Jan 1998 23:59:06 EST Most exploration geophones have a natural frequency above 8 to 10 HZ. The primary reason for this is to get rid of "ground roll "so it doesn't saturate the amplofiers. I don't envy your temperature at Fairbanks, Bob. I pulled a few winters on the North Slope. First time was the winter of 1948/1949. Seismic exploration for the Navy on NPR4 Regards, < A n Subject: Re: MA EVENT Date: Mon, 05 Jan 1998 21:34:02 -0800 Stephen -- I'm no expert in statistics, to say for sure that there is a relation between events across the globe would take quite a bit of statistical (computer) crunching. But, I think it's true that peoples brains (massive networks of neural nodes) are capable of discerning patterns that would take a lot of crunching by conventional computers to identify. And too, I've seen my brain (and others') be fooled by what appears to be a correlation and really isn't. I guess what I'm saying is that I'm not ready to say that these seeming correlations are anything abnormal, statistically. I've just uploaded my trace of this morning's Chino event. -- Karl At 10:36 AM 1/5/98 -0800, you wrote: >I'm really beginning to suspect the interrelatedness of these events all over the >world, and most especially on the opposite sides of the rim. > >And Italy seems to be still having more than its share of woes. Did you happen to >map this morning's event? _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "frank murray" Subject: RE: Global M5+ Activity - record tying sequence Date: Mon, 5 Jan 1998 21:45:40 -0800 > -----Original Message----- > From: Charles Watson [mailto:watson@................. > Sent: Monday, January 05, 1998 12:17 PM > To: Public Seismic Network Mailing List > Cc: QUAKE-L Earthquake Discussion List > Subject: Global M5+ Activity - record tying sequence > > I have not looked in the PDE catalogs prior to 1992, but does anyone > know how often this has occurred before this and if there have ever been > 9 consecutive weeks of 20+ earthquakes registering M5 or stronger? > hmmm...how far back might we trust the catalogs to be complete on M5 quakes??... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Marnie Gannon Subject: Re: LA peak velocties/acceleration Date: Mon, 05 Jan 1998 22:55:41 -0700 Edward Cranswick wrote: > > Charlie & Marnie- > Where are you getting your felt reports from? Edward, Since I live in Montana, I didn't feel it. ;^> I correspond with a number of people in the CA/LA area..seemed most people felt it first as a vibration and then a single jolt. If you need some felt reports from these areas I could probably gather them for you.. Marnie _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "David A. Nelson" Subject: new zealand a shaking Date: Tue, 06 Jan 1998 18:54:58 +1200 wow guys 3 unrelated events in one day all good size M4.5 and greater in the South Island of New Zealand. the latest only 1 hr befor this mail posted was so far the largest, they have been getting bigger as the day rolls on this is putting January 1997 to shame Dave Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson ZL4TBN 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: watson@................ (Charles Watson) Subject: Re: LA peak velocties/acceleration Date: Mon, 05 Jan 1998 22:21:22 -0700 Edward Cranswick wrote: > > Charlie & Marnie- > Where are you getting your felt reports from? Edward, I prepare professional regional and global earthquake graphics/reports for newspapers and television, and a few for the public as well. I have a pretty large following and get felt reports via phone, fax and the internet from domestic and worldwide sources. -- ---/---- Charles P. Watson, Consulting Geologist Advanced Geologic Exploration Seismo-Watch / Earthquake Information Services Voice: 702-852-0992 / Fax: 702-852-3226 Office Location: 39.43N 119.71W mailto:watson@................ http://www.seismo-watch.com _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: watson@................ (Charles Watson) Subject: Re: Global M5+ Activity - record tying sequence Date: Mon, 05 Jan 1998 22:24:57 -0700 frank murray wrote: > > > > > I have not looked in the PDE catalogs prior to 1992, but does anyone > > know how often this has occurred before this and if there have ever been > > 9 consecutive weeks of 20+ earthquakes registering M5 or stronger? > > > > hmmm...how far back might we trust the catalogs to be complete on M5 > quakes??... > probably 1960's, better as time goes on. For a while, I tracked M4+ events, but that went the way of the buffalo during the 1995 round of NEIC budget cuts. -- ---/---- Charles P. Watson _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Walt Williams" Subject: Re: MA EVENT Date: Tue, 6 Jan 1998 03:38:33 +0000 Hello All, For any one interested. I live in Canoga Park, which is a suburb of Los Angeles, California. The city sandwiched between Northridge and Chatsworth. Sherman Oaks, is located East of these three cities. We 'felt' 20...30 seconds of sharp shaking, which was preceded with a loud bang sound. Often, I 'feel' events minutes before I start to see posts here on the PSN-L. I have been quiet about posting comments about these 'felt' events as there is little useful data to be gained. My house is located slightly west of center of the so-called 'Valley' in the San Fernando Valley. Walt Williams, 98.01.06 dfheli@.............. Canoga Park, (LA suburb), California USA ------- Forwarded Message Follows ------- Date: Mon, 05 Jan 1998 18:04:37 -0800 From: Stephen Paul Organization: Built On Dreams To: PSN-L Mailing List Subject: Re: MA EVENT Reply-to: PSN-L Mailing List Edward Cranswick wrote: > Stephen- > You appear to be in a very sensitive site for picking up events -- and > this makes sense in terms of the concentrated pattern of damage to > Sherman Oaks by the Northridge Earthquake. What is your address? > -Edward > > Stephen Paul wrote: > > > > frank murray wrote: > > > > > if everybody could pop their times and locations into their posts, we could > > > all see the pattern of the waves... > > > > > > > -----Original Message----- > > > > From: Tom Frey [mailto:tfrey@............ > > > > Sent: Saturday, January 03, 1998 10:45 PM > > > > To: PSN-L Mailing List > > > > Subject: Re: MA EVENT > > > > > > > > > > > > Same Here!!!! > > > > > > > > > > > > > > > > Tom, > > > > As I mentioned to Larry, I didn't get the time, but my house really swayed down > > here in Sherman Oaks, San Fernando Valley area of So. CA > > -- > > Stephen Paul :^) > > > > _____________________________________________________________________ > > > > Public Seismic Network Mailing List (PSN-L) > > > > To leave this list email listserver@............. with the body of the > > message: leave PSN-L > > -- > Edward Cranswick Tel: 303-273-8609 > US Geological Survey, MS 966 Fax: 303-273-8600 > PO Box 25046, Federal Center cranswick@........ > Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L Edward, I am in the hills about 1 block E. of Woodman, and a mile or so south, and I would guess at an elevation of roughly 800-1200 ft. above the boulevard. Though many felt the event was 3-4 seconds, up here I definitely felt motion for 30-45 seconds. And you are so right. I can feel even the slightest tremors up here, which is a characteristic of being in the hills, mostly bedrock I believe, though more damage resulted here than in Studio City hills, my former residence for 10 years... I guess it's like being at the end of a stick where you can really fell the motion. What do you think of the 'ringing bell' hypothesis put forward some years ago? I tend to believe it... I read aboout it in an article in Scientific American some 6-7 years ago. Are you aware of it? -- Stephen :^) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Charlie Rond Subject: Re: web page Date: Mon, 05 Jan 1998 20:10:28 -0600 Sean-Thomas, You are doing good work and I am enjoying your Web Page. I've included a link to your vertical on the PSN-Memphis Web Page under "construction." Charlie Rond -\/\--Public Seismic Network-Memphis rond@................ (901) 360-0302 [ free BBS ] http://gandlf.ceri.memphis.edu/~rond http://gandlf.ceri.memphis.edu/~rond/psn _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Ted Blank Subject: Re: Trading Post! & Suggestions Date: Tue, 6 Jan 1998 07:22:55 -0800 (PST) I think the trading post is a great idea. I hope it can be kept separate from the discussions on the list so it will be quicker to scan the list of items for trade. Also, that list should have lower volume so would stay around longer. Regards, Ted > > Hello PSN-L, > > The idea of a 'Trading Post' is an interesting idea. In > the tradition of technical reflectors, items for swap / sale are > typically listed seperate to avoid clogging the 'data' channel. > Perhaps the PSN-L host could be asked nicely to provide a > separate list or web space? If not, and depending upon traffic (as I > am busy these days), I will offer some web page space for PSN-L list > members to post their offerings / wants. > > I pose a question: fellow PSN-Ls, do we really want 'spam' > co-mingled with normal dialog of the list? > > Best Regards, > > Walt Williams, 98.01.05 > dfheli@.............. > http://www.pacificnet.net/~dfheli > > Canoga Park, (LA suburb), California > USA > > ===================================================== > > ------- Forwarded Message Follows ------- > Date: Mon, 05 Jan 1998 08:54:54 -0600 > From: Mike Lozano > Reply-to: PSN-L Mailing List > Organization: Applied Sciences, Ltd. > To: PSN-L Mailing List > Subject: Re:Trading Post! > > Hi guys! > Trading post sounds like a great idea! Why don't I kick things off > with two offerings: > > 1 ea. FastVac DV-85/DV-142 Series Deep Vacuum Pump > BRAND NEW - NEVER EVEN PLUGGED IN! with spare Wankel-type cylinder > replacement kit (still in box), and 1 Qt. of oil (still sealed). > Purchased for around $400 for a project that never got off the ground. > Great for micro-barometry experimenters! > > 2 ea. DRSI Micro Data Link Controllers (packet radio system) Licensed > on commercial itinerant frequency in the 460 MHz band (5 watt > transmitter and cut-to-frequency rubber duck antennas on BNC > connectors. This system uses commercial packet standard, and is not > easily compatible with amateur packet. Used, but in MINT condition. > Purchased for around $1500. Set up your own remote seismic station! > > Mike Lozano, N0BDF > mikel@....... > > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: watson@................ (Charles Watson) Subject: Re: (Fwd) Re: MA EVENT Date: Tue, 06 Jan 1998 07:38:14 -0700 Thanks for the felt report, Walt. I use the felt reports in my Seismo-Watch earthquake reports - of course, just giving the regions it was felt and the extent of shaking. Since I am way up here in Reno, I often do not find out if the smaller (M3) temblors in California were felt sometimes till much later. With the Northern and Southern California offices of the USGS discontinuing their weekly earthquake bulletins there will be a significant loss of felt earthquake reports available to the public. I am concerned about this and have voiced my concerns to the appropriate parties. I would greatly appreciate an e-mail message if anyone feels an earthquake, no matter how big or small, or where ever you are on the planet. -- ---/---- Charles P. Watson, Consulting Geologist Advanced Geologic Exploration Seismo-Watch / Earthquake Information Services Voice: 702-852-0992 / Fax: 702-852-3226 Office Location: 39.43N 119.71W mailto:watson@................ http://www.seismo-watch.com _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Mike Lozano Subject: Seismic system Date: Tue, 06 Jan 1998 10:02:16 -0600 I'm sure it's not news to the "pro's" in the bunch, but my company did some work with the Bureau of Reclamation recently. They maintain their own seismographic system for Dam Safety. http://seismo.usbr.gov/quake/curWus.html covers Colorado, Wyoming and Idaho, as I recall. Mike Lozano, N0BDF -0- _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: bob@................. (Bob Hammond (USGS-AVO Geophysicist)) Subject: Re: oil exploration geophones Date: Tue, 6 Jan 1998 07:55:59 -0900 I know a seismologist who attempted to use oil exploration geophones (a pair, actually) in lieu of 1 Hz seismometers for his regional seismic network. While they did indeed respond to very local earthquakes, their output was just not adequate due to the mass and coil being so small. By the way, my hat's (but not my coat, it's still too cold here) off to Sean Thomas for his design and construction of his VBB seismometer! It's "way cool"! I might just have to build a few and put them in the schools I work with instead of the short-period verticals I use now. George Erich: I'd like to hear more about your winter experiences on NPR4 in 48/49. regards to all, Bob Hammond APSN Fairbanks _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: lahr@.................. Subject: mpeg player Date: Tue, 6 Jan 1998 10:24:41 -0700 (MST) I found that the VMPEG viewer listed on this page worked well with Windows 95. http://www.mpeg.org/pointers/MPEG-video-player.html I was able to view the video that Edward mentioned, located at: http://www.seismo.berkeley.edu/seismo/events_of_interest/3dmod/3dmod.html The player that comes with Windows 95 did not work for me. I also tried one called MPEGPLAY. It only displayed a black and white picture for the small video's and required a $25 registration to play a larger video! The earthquake videos are in color and look great with the free VMPEG viewer. JCLahr _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: kathy mortensen Subject: Re: DATAQ DI-150RS Date: Tue, 06 Jan 1998 14:27:25 -0700 Dennis Eckert wrote: > > I'm pretty new to all this monitoring, and been thinking about the DATAQ > logger. But I don't have the COM1 conflicts that you do. Since you dint > specify what computer you are using, is it possible your motherboard has a > PS/2 connector on it? If so, you either buy a PS/2 mouse or get an adapter > cable to convert your RS-232 mouse to a PS/2 mouse and free up that RS-232 > port! > > BTW, the RS232 mice are the slowest ones and that is why so many folks use > the PS/2 connector. > > Now, the bit question: What device is the input to your DATAQ card? and is > it the DATAQ software that gives you the "alarm" you talk about? > > Dennis Eckert KB7ST (Amateur Radio Operator) > Flies Standard Cirrus sailplane (SV) > In Western & Eastern Washington > > ICQ 4324132 > -----Original Message----- > From: kathy mortensen > To: psn-l@............. > Date: Sunday, January 04, 1998 9:03 PM > Subject: DATAQ DI-150RS > > >O.K. I just found the PSN mailing list about 3 weeks ago and have been > >glued to my > >email. I was intriged with Sean Thomas Idea of using the Radio Shack > >dvm as a data > >recorder. I've been looking for an economical way to record my > >seimograph signals. I have a clone, no PS/2 connection. I'm using com4 IRQ5 --so far no problems, except, I can't log and go on the web or even use my regular windows! Eventually I want to get a dedicated system. The bit answer: The DATAQ is a module that has a cable to connect to a serial port (9 pin) (I use an adapter and connect to my spare 25 pin serial port, the one I had to disable to hook up my modem -- long story). The alarm that I was refering to is on my amplifier board. I don't know enough about the DATAQ software yet to know if they have any alarms, well except for the beep for file full. If I find any, I'll post! The DATAQ DI-150RS is a 2 ch. (or 1 ch. differential) with a therm 1 and 2, (which I haven't figured out yet) and an excitation input (up to 15 volts) with an excit + and - for use with a bridge network. More as I learn!! SKM ICQ 6314138 email mortskm@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Norman Davis WB6SHI Subject: Re: Geophone Date: Mon, 05 Jan 1998 20:39:31 >I use a Mark Products L4 geophone which is sold by the RT Clark, Co. I suggest using this geophone >as a short-period vertical sensor for amateur seismographs because it a 1-Hz seismometer, has good >response, and is used by virtually all of the university and government seismograph networks in >the US. Well bob keep mind the word amature. At 375 a piece I can get a lot of 4 hz phones for that price. Norman Davis WB6SHI Email normd@............. Shingle Springs, Ca, USA it ain't local... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: bob@................. (Bob Hammond (USGS-AVO Geophysicist)) Subject: Re: Geophone Date: Tue, 6 Jan 1998 14:53:08 -0900 Norm Davis: Yes, I agree the L4 is high cost compared to 4 Hz geophones. TANSTAAFL. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: Global M5+ Activity - record tying sequence Date: Tue, 06 Jan 1998 08:28:37 -0800 Frank I agree with Charles. It may go back to the mid 40's in the US. Barry Charles Watson wrote: > > ---/---- > Charles P. Watson > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: PSN records for M. Antolik - Map / MPEG viewers Date: Wed, 07 Jan 1998 00:31:13 -0800 Thanks for everyone's help. I was able to use the MPEG viewer at http://www.intervu.net/. This Netscape plug-in worked just fine on the larger MPEG files. Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "David A. Nelson" Subject: yet another good sthrn new zealand event Date: Thu, 08 Jan 1998 01:55:25 +1200 Hi all, SW offshore NZ rocking again, these events really show the ability of 4.5 Hz geophone to perform excellently for local and regional quakes These events are all around 390 to 420km (240 to 260 miles) from my home/sensors the 6 quakes I have recorded in the last 2 days have all been captured by the geophones with no trouble at all. I highly recomend geophones for local and regional activities as their small size, ease of installation, zero maintenance and low cost make them invaluable for amateur activities. They also make a perfect companion to other low freq. teleseismic sensors such as the Lehman seismometer. Cheers Dave Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson ZL4TBN 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: bob@................. (Bob Hammond (USGS-AVO Geophysicist)) Subject: Dave Nelson email about 4.5 Hz geophones Date: Wed, 7 Jan 1998 08:48:17 -0900 Sorry, folks, I was obviously wrong about 4.5 Hz geophones being worth using! I based my opinion on my one and only exposure to using them for regional seismograph networks. I stand corrected, Bob Hammond APSN Fairbanks "think twice, email once" (a spin on that old carpenter's rule) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ERICH777 Subject: Another Small Southern California Event Date: Wed, 7 Jan 1998 14:13:09 EST Hello All Time: 09:50 Date: 98/01/07 Station Location 33,51.00N 118,8.33W Remarks; P delta time to S indicates about 18 miles from me Magnetude M3.XX ? I was away from home when this event occurred and heard about it on my car radio. I did record it with my 4.5 HZ geophone. < A n Subject: 1 hz from 4.5 hz phones; Date: Wed, 7 Jan 1998 13:41:27 -0600 (CST) They can be used for lower frequency work by using very low noise amplifiers to make a 2-pole low pass filter with a gain of about 100, with a corner at 1hz or less. Also, there is a better equalizer circuit board you could get from Sprengnether Instruments Co. (314 535 1682) that is based on an article by P.M.Roberts in BSSA, vol 79, No. 4, Oct 1989. It makes the 4.5 hz phone response look like the L4-C. I don't know what it costs, but it might be around $50. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Marchal, Lare van" Subject: 1 hz from 4.5 hz phones; Date: Wed, 7 Jan 1998 17:36:52 -0500 > They can be used for lower frequency work by using very low noise amplifiers to make a 2-pole low pass filter with a gain of about 100, with a corner at 1hz or less. < = I use this kind of filter with my 4.5 Hz geophones. Last month they detected the two Jan Mayen events (both M5+) about 1800 Km north of my home here in Holland. Bye for now, Marchal van Lare Nieuwvliet, Holland 51.38 N 3.50 E _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Roger Sorensen Subject: Re: 1 hz from 4.5 hz phones; Date: Wed, 07 Jan 1998 15:53:24 -0800 Is there somewhere we can find out more about this filter/amp setup? Any Web pages? Thanks Roger (KD6LQE) Chatsworth, CA USA > They can be used for lower frequency work by using very low noise > amplifiers to make a 2-pole low pass filter with a gain of about 100, > with a corner at 1hz or less. > > I use this kind of filter with my 4.5 Hz geophones. Last month they > detected the two Jan Mayen events (both M5+) about 1800 Km north > of my home here in Holland. > > Marchal van Lare _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jeff Batten Subject: test-ignore Date: Wed, 7 Jan 1998 20:15:37 -0800 (PST) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "David A. Nelson" Subject: Re: 1 hz from 4.5 hz phones; Date: Thu, 08 Jan 1998 17:43:24 +1200 At 05:36 PM 1/7/98 -0500, you wrote: They can be used for lower frequency work by using very low noise >amplifiers to make a 2-pole low pass filter with a gain of about 100, >with a corner at 1hz or less. >I use this kind of filter with my 4.5 Hz geophones. Last month they >detected the two Jan Mayen events (both M5+) about 1800 Km north >of my home here in Holland. Bye for now, Marchal van Lare >Nieuwvliet, Holland >51.38 N 3.50 E Hmmmm Marchal by cutting off at 1 Hz u are loosing a lot of valuable seismic data. Local and regional events are very rich in higher freq signal. I far more reccomend a 10Hz filter and then u dont miss that data if the event is teleseismic with a mainly lower freq content then u can use software filtering to get rid of any higher freq manmade noise that may be present i would not even consider using a 1 hz filter myself as u are really defeating the good ability of the geophone also most of the geophones have very severe low freq attenuation (that is they dont respond well) below their resonant freq. so their output there is very low. for ur thoughts Dave Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson ZL4TBN 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Al Allworth" Subject: Re: L4 Geophone Date: Wed, 7 Jan 1998 21:15:33 -0800 -----Original Message----- From: Bob Hammond (USGS-AVO Geophysicist) To: psn-l@............. Date: Monday, January 05, 1998 10:58 AM Subject: Re: Geophone > Norman Davis, et al: > >I use a Mark Products L4 geophone which is sold by the RT Clark, Co. I suggest using this geophone >as a short-period vertical sensor for amateur seismographs because it a 1-Hz seismometer, has good >response, and is used by virtually all of the university and government seismograph networks in >the US. Keep in mind that geophones normally used in oil exploration are 2 Hz geophones and are not >as good for monitoring regional and local earthquakes as a 1 Hz instrument. The L4 comes with a >calibration coil and is marked as a L4-C. You don't need the cal coil. > >regards, > >Bob Hammond Has anyone seen the internal construction of the L4 geophone? I have several 1 Hz. units and was wondering if a displacement transducer could be added to enable a force feedback conversion. How is the calibration loop used with the L4? Mine are labeled "Seismometer". I have seen others labeled geophone. Is there a difference or only the application? _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Marchal, Lare van" Subject: Re: 1 hz from 4.5 hz phones; Date: Thu, 8 Jan 1998 10:19:16 -0500 Dave Nelson wrote: > by cutting off at 1 Hz u are loosing a lot of valuable seismic data. Local and regional events are very rich in higher freq signal. < Yes , Dave, I totally agree with you. Last month I experimented for some time to see what would happen when I use a 1 Hz-filter with 4.5 Hz geophones. I was very surprised to see my seismo was able to detect M5's at 1800 Km.= Cheers, Marchal van Lare Nieuwvliet, Holland (51.38 N 3.50 E) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: Re: 1 hz from 4.5 hz phones; Date: Thu, 8 Jan 1998 00:19:47 -0600 (CST) The response of a geophone rolls off with omega**2 below its' natural frequency. so the voltage output of a 4.5 hz phone is down by a factor of 20 at 1 hz which is where regional and teleseismic p-waves show up. A contour filter or the better equalizer circuit makes up for this loss, the idea is not to attenuate the high frequency response, but to bring up the lower frequency response to a useful level above the electronic noise or the lsb of the DAC. When the fc is properly selected (somewhat below 1 hz, per the math), the 4.5 hz phone will look like a 1 hz phone. This in no way reduces its' high frequency response. We use 1 hz phones for data from 0.1 to 30 hz for regional network stations; ground motion studies require the broader response. Regards, Sean-Thomas St. Louis University _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Karl Cunningham Subject: Re: 1 hz from 4.5 hz phones; Date: Thu, 08 Jan 1998 08:15:31 -0800 Hi -- I've not tried this circuit with phones, but it should work. It is a basic 2-pole low-pass non-inverting topology. This, along with an amplifier before it should compensate for the second-order roll off of the geophone. Using a third-order filter (add another resistor and capacitor -- I can provide component values if anyone wants) will provide high-frequency attenuation too, if this is desired. Many filter characteristics are in common use. Bessel provides linear phase-to-frequency relationship around the cutoff frequency, which tends to preserve the "look" of the resulting waveform. The values for a two-pole Bessel filter are calculated as follows: C1 = 0.6667F C2 = 0.5F R1 = R2 Choose a value for R1 and R2 that is high -- say 10K or 100K. Now, for desired cutoff frequency f, multiply the above capacitor values by 1/R*w, where R is the chosen resistor values, and w is 2*pi*f. So, for f = 4.5Hz and R1=R2=10K, C1=2.36uF, and C2=1.77uF. | | C1 +------| |----------------+ | | | | | |\ | R2 | R2 | \ | o----\/\/\-+--\/\/\--|-----|+ \ | | | \ | --- | >---++------------o C2 --- | / | | +--|- / | | | | / | | | |/ | | | | | +-----------+ | --- \ / V For the amplifier stage, I'd put it before the filter so the drift of the filter stage is not being amplified too. Just use a good low-drift op-amp. Gain is R1/(R1+R2). |\ | \ o--------------------------|+ \ | \ | >---+-------------o | / \ +--|- / / | | / \ R1 | |/ / | | +-----------+ | \ / \ R2 \ | --- \ / V Karl Cunningham La Mesa, CA. PSN station #40 karlc@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Karl Cunningham Subject: Re: 1 hz from 4.5 hz phones; Date: Thu, 08 Jan 1998 09:21:51 -0800 Ooops. There must be a correlary to Murphy's law that says I won't realize my mistakes until they are published... I had the wrong idea about conditioning the response of the geophones. What is really needed is for the cutoff frequency of the filter to be set to the low frequency of the desired response (1Hz in the example), and the gain of the amplifier stage be set to make up the difference (20:1, in this case), as Sean-Thomas has suggested. Karl Cunningham La Mesa, CA. PSN station #40 karlc@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: L4 fedback? Date: Thu, 8 Jan 1998 11:30:03 -0600 (CST) Bob, Al, and co., I have been overhauling L4-C seismometers for the past 23 years, and I have a collection of them in various states of (dis)repair. The usual problem is that the suspension sags over time, and the internal spacers have to be rearranged to raise the mass, which is difficult to do and still retain the 1-second To. (A temporary solution to a sagging mass is to tilt the seis about 10 degrees, until the mass centering tester indicates it is off the bottom stop). Other problems are the fine connection to the cal coil (I always use them) get fried from accidental contact with a voltage, or the whole thing gets sparked up when lightning hits the telemetry antenna and tries to find ground through the seis by puncturing the thick ABS pipe it is installed in. I tried to use the L4 with feedback several years ago, using the VRDT transducer (the LVDT won't work because the mass rotates slightly as it moves with the multiple circular leaf-spring suspension.) THe problem I had was that all my L4s have 5500 ohm coils, which is way too much resistance for the feedback coil: the response becomes an oscillator, even using half the coil. Mark Products has made low resistance coils, but they are hard to find. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: 4.5hz equalizer Date: Thu, 8 Jan 1998 11:52:06 -0600 (CST) For improving the response below To, I strongly recommend looking at the article : "A Versatile Equalization Ciruit for Increasing Seismometer Velocity Response Below the Natural Frequency", P.M.Robarts, BSSA, Vol 79, No 4, Oct. 1989. For proper equalization of the response, a unity gain amplifier is used in parallel with the low pass stage, so that the response above the filter is restored; the output of the parallel stages is then summed with another amplifier. But using a second-order low pass to correct the omega**2 rolloff presents phase problems near zero voltage (see the article), so two stages are used, but with only first order (single pole) filters, and each with its' parallel unity gain follower and summing amplifier. So a total of 6 amplifiers is needed, which is why a 2-pole low-pass filter is a partial solution; it, however, does not restore the higher frequency response. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Doug Crice Subject: Re: 4.5hz equalizer Date: Thu, 08 Jan 1998 10:01:30 -0800 The response curve of a geophone looks roughtly like this: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx x x | x | db x f x x x x where f is the natural frequency of the pendulum. The behavior at the corner varies with the damping from an upward peak (underdamped) to a smoother rolloff (overdamped). The slope of the attenuation curve is 12 db/octave. So, to make it look more like a 1 Hz geophone, you need to feed the signal through a filter which flattens the response. Something that looks like this: x x x x x db x f x | x xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx You want the gain of this filter to be 1 (well constant anyway) above the natural frequency, and you want increasing gain below that frequency with a slope of +12 db/octave. This should theoretically extend the frequency response of the geophone indefinitely downward until of course noise becomes as big as the signal. For example, at 0.25 Hz, you would need about 48 db of gain just to get a flat response. Karl's 2-pole lowpass (high cut) circuit is not strictly correct; it has the slope but the flat spot is in the wrong place. xxxxxxxxxxxxxxxxxxxxxxx x x x x db x x x x So, depending on where the corner is, you don't get the low boost and you lose the high frequencies. I would guess that the article Sean refers to has the right circuit. Doug Crice _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Roger Baker Subject: Re: L4 fedback? Date: Thu, 08 Jan 1998 12:31:51 -0600 Friends, I am not familiar with specific geophones, but the ones I have seen in the literature have something like a alnico cylinder magnet hanging vertically from a springy suspension and inside the high resistance sensing coil. Would it not be possible to wind a tubular low resistance feedback coil on the outside of the geophone, assuming a geophone is really that simple in principle? The instantaneous power demand on such a coil might be high and might require watts of peak output, but the average power demand should be low. Comments? --Yours, Roger Baker At 11:30 AM 1/8/98 -0600, you wrote: >I tried to use the L4 with feedback several years ago, using the VRDT >transducer (the LVDT won't work because the mass rotates slightly as it >moves with the multiple circular leaf-spring suspension.) THe problem >I had was that all my L4s have 5500 ohm coils, which is way too much >resistance for the feedback coil: the response becomes an oscillator, >even using half the coil. Mark Products has made low resistance coils, >but they are hard to find. > > > >Regards, >Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jack Ivey Subject: RE: L4 fedback? Date: Thu, 8 Jan 1998 14:01:54 -0500 I'm surprised that coil resistance is a fundamental limitation. Couldn't you use a current source to feed it? Jack Ivey ivey@.......... > > > >I tried to use the L4 with feedback several years ago, using the VRDT >transducer (the LVDT won't work because the mass rotates slightly as it >moves with the multiple circular leaf-spring suspension.) THe problem >I had was that all my L4s have 5500 ohm coils, which is way too much >resistance for the feedback coil: the response becomes an oscillator, >even using half the coil. Mark Products has made low resistance coils, >but they are hard to find. > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: Re: L4 fedback? Date: Thu, 8 Jan 1998 15:47:15 -0600 (CST) Roger, Jack, & co. In most geophones the coil moves, not the magnet. In the 50's there were a lot of moing-magnet seismometers, including the impressive Johnson-Matheson with a 20? kg mass. Unfortunately, as the sensitivities were cranked up, the moving magnets were found to be moving around because of geomagnetic storms and local distrubances, like cars moving by. So with a moving coil, it is also the effective mass.In most small phones (and the L4-C) the signal is coupled out through the suspensions at each end. Also, the windings are split and wound in opposite directions to cancel any externally induced voltages (they are also at opposite ends of the magnet); the coils are usually wound within brass cylinders and impregnated with epoxy, ie not even repairable. Regarding the resistance of the feedback or force coil in a triple feedback broadband configuration: the object isn't just to get a current to flow through the coil. The current is the summation of three characteristic currents, each producing a different result (proportional, differential, and integral functions of the displacement voltage) that result in an acceleration of the mass due to these currents. In the transfer function, the force coil resistance is a coefficient of the fourth-order term; if it is at all large, the term "blows up". You can see this in the transfer function available in the figures, etc, section at: http://www.eas.slu.edu/People/STMorrissey/index.html Also, in the report in the "seismometer" page, there is a table of parameters of known VBB seismometers, which shows the coil resistances used. And believe me, if the German, Swiss, and British manufacturers of VBB sensors could make high resistances work, we would see it. Regards, Sean-THomas St. Louis Univ. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Marnie Gannon Subject: Live Internet Seismic Server Date: Thu, 08 Jan 1998 14:50:42 -0700 Hey Guys, Forgive me if I already sent this link, http://aslwww.usgs.gov/Seismic_Data/liss.htm/ but wanted to be sure you saw it..online seismograms from stations around the world.. Also a very good link page..http://www.cco.caltech.edu/~meltzner/seismolinks.html which includes the new address for KNBC seismogram Marnie > > Live Internet Seismic Server > > The Live Internet Seismic Server (LISS) allows mulitple users to > receive near-real-time seismic data in a relatively passive way. > Specific data requests are not necessary, nor are individual dial-up > or telnet sessions to seismic stations. Once the software is running > on the host machine and connected to the LISS and desired port, SEED > binary data files are converted to ASCII and may be stored in a > rotating buffer, for example, enabling the user to access live and > recent data at will. > > [Image] Connecting to the LISS > > [Image] Telemetry status > > [Image] Map of telemetry stations and recent earthquakes > [Image]Live data - Helicorder Plots - Updated every 30 > minutes[Image] > > [Image] Preceding two hours of data from all stations > > > > [Image] > > Return to Seismic Data Page > > This page is URL: > Maintained by: webmaster@............... > Last modified on December 3, 1997 (gws) http://aslwww.cr.usgs.gov/Seismic_Data/liss.htm _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: shammon1@............. Subject: [Fwd: time url] Date: Thu, 08 Jan 1998 20:25:36 -0800 This is the URL for the WEB time to set a PC clock via the NBS WEB site. http://www.bldrdoc.gov/timefreq/javaclck.htm From: wb6nvo@............. (Jim Skinner) Subject: BSSA back issues availability Date: Thu, 8 Jan 1998 21:41:46 -0700 (MST) - To all - I have noticed the traffic for the last few days concerning papers/articles published in the Bulletins of the Seismological Society of America. They are currently clearing out a lot of "back issues" that they have extra copies of. The latest BSSA issues discussed in this forum were the 4.5 Hz filter scheme in BSSA , vol. 79, No. 4 , Oct 1989 and "The Leaf- Spring Seismometers: Design and Performance" BSSA , vol. 72, No. 6 , Dec 1982 (this vol is a 2 vol. set; the article is in "6A"). I talked with Kathy at the SSA today and BOTH volumns are still available.....Price I was quoted was $16.50 for both (shipping is included). If anyone is interested call Kathy @ (510) 525-5474 or send her a check (payable to: Seismological Society of America) Seismological Society of America 201 Plaza Professional Building El Cerrito , Ca. 94530-4003 They can take a credit card providing they have a signature. By the way....membership is only $100 per year ($110 outside U.S.) and is worth many times that for the periodicals alone (BSSA and SRL bulletins). I highly recommend membership in this Org. Congrats to Sean-Thomas Morrissey and Charlie Watson for joining (was published in the SSA , BOD meeting minutes in the SRL). - Jim Skinner - Tucson, Ariz. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: Trading Post? Date: Thu, 08 Jan 1998 21:06:56 -0800 My .02 cents... I like the idea... I think this list and a Web page could work out OK. People could make their announcement using this list (I don't think another list just for this is warranted) and a web page could be used to archive the unsold/untraded equipment. I have no problem hosting the web page BUT someone else will have too manage it. I have enough things on my plate... I think we should limit the equipment to seismic monitoring equip. (sensor etc), computer equip., electronic equip. (test equip. parts etc), and EQ safety equip, and maybe others... As I write this Jim Skinner sent out an excellent message about past issue of Bulletins of the Seismological Society of America. This type of message could also be archived on the PSN Trading Post Web page. So if we are going too do this we are first going to need a volunteer to keep the web page up to date. For the first go around I think we should email the info directly to the person who will manage the page. This will cut down on the number of initial post directly to this list. After the web page gets created, and as new items become available, they could be posted to this list and the email messages can be archived on the web page until the equipment gets sold or traded. Larry Cochrane Redwood City, PSN At 08:19 PM 1/4/98 -0700, you wrote: >Hi everyone, > >This is tentative in thought...Is anyone interested in trading >whatever for whatever?? I know for myself... I have a >surplus of old stuff I'll likely never get around to using. > >Expect there is afew out there in the same surplus condition, >who would treasure someone else's endless storage goodies. > >This avocation cost can be considerable over a period of >time and a swap may bring a faster and cheaper solution >than commercial approaches. Guess it would be fun too. > >I'am sure that an endless email approach is not desired over >the PSN machine. Perhaps, for those interested they >could privately communicate outside PSN per their own >individual email. It should be possible to make it a swap >only....no cash involved....except for postage costs. > >Anyway....being as this is just a thought...what do you >think? Rules? Limitations? Gone Fishing in this PSN >pond.........?? > >Thanks, Meredith Lamb _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Al Allworth" Subject: Re: [Fwd: time url] Date: Thu, 8 Jan 1998 23:42:33 -0800 -----Original Message----- From: shammon1@............. To: psn-l@............. Date: Thursday, January 08, 1998 7:25 PM Subject: [Fwd: time url] >This is the URL for the WEB time to set a PC clock via the >NBS WEB site. What happened to the URL? My reader didn't show it. I would be interested in getting this URL. Al Allworth allworth@.............. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: TMichel917 Subject: 4.5hz equalizer Date: Fri, 9 Jan 1998 10:31:59 EST There=B4s another way to extend the frequency range of a geophone, develo= ped 15=0Ayears ago by Lippmann. This method is based on an overdamping of= the geophone=0A(similar to the method used in feedback seismometers - it= =B4s based on an=0Aflattening of the response curve by increasing the dam= ping=0Awith an electronic feedback network.).=0AAs a geophone - especiall= y the cheap ones for prospecting work - has only one=0Acoil, the damping = can only be increased by lowering the damping resistor.=0AUnfortunately t= he damping of a shorted geophone isn=B4t high enough - and the=0Aoutput v= oltage is zero. The solution is to replace the damping resistor by a=0ANI= C (negative impedance converter). A NIC is an OP-AMP-circuitry which=0Asi= mulates a negative resistance. With an appropriate negative resistance th= e=0Aoutput of the geophone in the interesting area is no longer proporti= onal to=0Aground velocity above the natural frequency and proportional to= the derivative=0Aof the ground acceleration below it, but proportional t= o ground acceleration=0Aaround the area of the former natural frequeny. T= o get an output proportional=0Ato ground velocity, the output of the NIC = has to be integrated only once by an=0Aelectronic integrator. This method= has some advantages over the method with an=0Ainverse linearisation netw= ork:=0A=0A1. Better linearity because of the smaller displacement of the = internal mass.=0A=0A2. Better Signal-to-noise-ratio because only a one-st= age integrator is used=0Aand lower amplification=0Ais needed and therefor= e a better dynamic range.=0A=0AIt also has advantages over seismometers w= ith a lower natural frequency:=0A=0A1. Robust and unsensitive against har= sh handling.=0A=0A2. Unsensitive against improper leveling.=0A=0AThis met= hod is patented and used by lennartz electronic=0A(http://www.hway.net/le= nnartz), Germany, in their LE-xD/x product line. Their=0Alatest version i= s the LE-3D/20s, a triaxial seismometer with a corner period=0Aof 20 s, w= hich uses 1 Hz geophones. The first model, the LE-3D, is a 1 Hz=0Awhich u= ses cheap 4.5 Hz prospecting geophones.=0A=0ARegards,=0A=0ATorsten=0Ators= ten@............ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Doug Crice Subject: Lennartz geophone Date: Fri, 09 Jan 1998 08:45:27 -0800 Torsten: Fascinating stuff about the Lennartz geophone compensation. Unfortunately, the link seems to be obsolete and I couldn't find a new one on the search engines. Also couldn't find any reference to Lennartz geophone on the IBM patent search home page. Can you provide us with a contact point or new URL? Doug Crice _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: shammon1@............. Subject: Re: [Fwd: time url] Date: Fri, 09 Jan 1998 10:23:25 -0800 http://www.bldrdoc.gov/timefreq/javaclck.htm Here is is again. URL to NBS time Regards, Steve Al Allworth wrote: > > -----Original Message----- > From: shammon1@............. > To: psn-l@............. > Date: Thursday, January 08, 1998 7:25 PM > Subject: [Fwd: time url] > > >This is the URL for the WEB time to set a PC clock via the > >NBS WEB site. > > What happened to the URL? My reader didn't show it. I would be interested > in getting this URL. > > Al Allworth > allworth@.............. > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Karl Cunningham Subject: Re: 4.5hz equalizer Date: Fri, 09 Jan 1998 09:41:10 -0800 At 10:31 AM 1/9/98 EST, Torsten wrote: >The solution is to replace the damping resistor by a > NIC (negative impedance converter). A NIC is an OP-AMP-circuitry which > simulates a negative resistance. Torsten & the gang -- I experimented with this approach while working on my horizontal FB unit. It worked VERY well, with a period in excess of 1 HOUR! (The natural period of the Lehman-style mechanical system it was mounted on was about 15 seconds) The only problem was that the noise and stability requirements of the op-amp and resistors were quite severe to get this kind of long-period performance, and the change in resistance of the coil with temperature needed to be compensated for. I'm sure that with a good chopper-stabilized op-amp and good resistors, one could make it work for shorter periods with no problem. The design is very simple, since it uses the same coil/magnet for both the velocity transducer and the feedback, and electronics amounts to only an op-amp and a half-dozen resistors, then the integrator stage to get velocity. I think that one could make an ok horizontal seismometer by attaching a mass to a loudspeaker cone and connecting it to the NIC electronic circuit. Air currents would be a problem using a speaker, but it makes a very simple arrangement. Karl Cunningham La Mesa, CA. PSN station #40 karlc@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: TMichel917 Subject: Re: Lennartz geophone Date: Fri, 9 Jan 1998 13:57:18 EST Hi Doug,=0A=0Aunfortunately the URL of lennartz electronic is down since = some days or weeks=0Aand I don=B4t know another. Maybe you can get infor= mation about their email-=0Aaddress: lennartz@.................. patent i= s a german one and its number is DE 33 07 575 C2. This is nearly=0Athe on= ly information source about the circuitry, and it doesn=B4t include any= =0Ainformation on how to get the circuitry really work.=0A=0AIf you have = special questions about it I will try to help you.=0A=0ARegards=0A=0ATors= ten=0A _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Ken Navarre Subject: Problems with USGS finger server... Date: Fri, 9 Jan 1998 16:18:44 -0800 (PST) Anyone else notice that the finger server for quake@................. has been down for a couple of days now? Ken _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: wizard@......... (Rick Jerome) Subject: USGS Server Date: Fri, 09 Jan 1998 16:30:09 -0800 Yes it has been SLOW when it does work. Noticed it about noon PST yesterday. ------------------------- Michael D wizard@......... N6EGQ Tuolumne, CA ------------------------- "With our ears may we hear what is good." Mundaka _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: Re: J-M, etc. Date: Fri, 9 Jan 1998 19:34:30 -0600 (CST) Bob, The J-M seis was a workhorse of the AFOSR programs, like at TFO. We also had a bunch of them in the Aleutians. I once told the students from CIRES (univ of colo) that they could have one if they could find it. They chased the cable for miles in the tundra; I failed to tell them that it was buried in an oil drum about 4 meters deep and weighed about 150 lbs; the thick steel case provided good magnetic shielding. Our main noise problem there was the wind. Being students, they DID recover the seismometer. I haven't looked at the Benioff question. I would be inclined to use the all-parallel configuration and directly measure the constant with a small mass and a VRDT as a null indicator. Because of the mutual inductances, I'm not sure how accurate a result can be obtained by using series/parallel calculations. Several years ago, I also looked at the S-13 as a possible feedback candidate, but all of mine have high Z coils. We are currently using sets of them as part of the Nuclear Non-Proliferation Test Ban Treaty verification effort. They are co-sited at our broadband stations, and equipped with high gain amplifiers and 24-bit digitizers. Someday I will put some photos of the station in the cavern (CCM) on the web page. I have some "extra" 24-bit channels there, and I hope to use one of them to directly compare the STM-8 with the STS-1s; the channels are currently being used for the microbarometers. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: Re: L4 Seismometers Date: Fri, 9 Jan 1998 20:03:24 -0600 (CST) Al, Nice find of the L4-C seismometers. Mark Products is currently getting $1100 for new ones. Some of your questions: (I have data sheets on them if you can send me a FAX number or SASE). The L4-C is a 1hz sensor, the L4-A is 2 hz (rare) The 23.9 Kdyne/A is the calibration coil constant. The 500 ohm coil has an output of 83 v/m/sec, and takes a shunt resistance of 810 ohms for critical damping. Often this damping resistance is installed at the underside of the connector at the factory. I usually also install 100 ohms in series with the calibration coil to protect it from excessive current. Dismanteling them runs the risk of ruining them. There are stacks of etched leaf-spring suspensions and spacers. The case is opened at the top by pulling the roll pins, or by slitting the case above them and removing the cover; new holes are drilled to replace them. Open the unit inverted, as this clamps the mass. there is one screw at the bottom insulator that holds the whole thing together. If you re-arrange the suspension elements, you probably won't get 1hz again; often it won't even lift the mass; Mark Prod. makes a secret as to how they get the mass suspended with a To of 1 second. Also, the coils are potted in the brass cylinders that make up the mass. regards, Sean-Thomas BTW: some of you are mailing html stuff that is unreadable to most mail readers. I use the old-fashioned UNIX "Mail" that was invented before html. Listing a URL is more useful. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: VBBsensor Date: Fri, 09 Jan 1998 22:14:20 -0800 Sean Thomas I got MCAD working. My 1 sec, .5 kg, 6" vertical sensor seems to have a low frequency knee at 10 sec or so. I have tried to vary the mass, resistors and feedback cap trying to lower the frequency of the knee. The velocity output is more sensitive to certain component values and not so sensitive to others. I found increasing the feedback cap size to do the most good.If I can increase the mechanical free period to 1.5 sec it will help. Any suggestions? Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: watson@................ (Charles Watson) Subject: China quake, bad news Date: Sat, 10 Jan 1998 09:15:47 -0700 Did you hear that over 47 people were killed from the M5.8 quake in China. *sigh* -- ---/---- Charles P. Watson, Consulting Geologist Advanced Geologic Exploration Seismo-Watch / Earthquake Information Services Voice: 702-852-0992 / Fax: 702-852-3226 Office Location: 39.43N 119.71W mailto:watson@................ http://www.seismo-watch.com _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: Re: L4 Seismometers Date: Sat, 10 Jan 1998 11:21:56 -0600 (CST) Ken and co: Ken, One of the wildcards for L4 seises IS the connector: it can be a 6-pin circular pattern, a 6-pin T pattern, a 10-pin full pattern, or a 4-pin square. It is also easily changed because it is a common "06" (I think) MS-type Bendix or Amphenol shell size, (available from Newark, or often electronic surplus) and the connections from the inside wiring and case ground are soldered directly to the back. (If you change it, be sure to add some ohms to the calibration circuit so it can't be burned out by a battery; I had a technician once burn out a bunch of them with a wrong setup, while he "proved" that all of them were open. BTW: a common problem withthe L4 that results from rough handling is a very short mechanical period that results when one of the diaphram leaf springs inverts. It can usually be remedied by a firm blow with the base of the palm of the hand to the side of the case. For handling, the seis should be kept upside down and the short jumper installed across the output pins to damp any movement of the mass. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: Re: VBBsensor Date: Sat, 10 Jan 1998 11:35:18 -0600 (CST) Barry, It sounds like you are getting there. BTW, we usually refer to the changes in slope of the response curve as "corners" ("low frequency corner") even though they look like knees. I use MATHCAD to run an iteration or a sweep of the important values to see what they do. You didn't mention what integrator time constant TI you were using. Usually the effective period comes out somewhere near TI, although you can get a 40-second response with a 20-second integrator. Increasing C does raise the overall output, but rounds out the response away from the desired flat velocity response. If you want me to double check your figures, I need all the values (M, To, Gn, Rn, C, Rp, TI, and RI) you are using. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: VBBsensor Date: Fri, 09 Jan 1998 23:48:22 -0800 Sean Thomas Here's what I started with and what I thought was an improvement Start Current M 0.457kg 0.6 T0 1 sec 1.5 GN 12.653 12.653 Radio Shack speaker RN ? ? C 24e-6 60e-6 RP 5.61e5 1.5e6 TI 80.4 80.4 RI 1.07e5 1.07e5 r 234,000 234,000 Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Roger Baker Subject: Seismometers Date: Sat, 10 Jan 1998 14:20:58 -0600 Well Sean-Thomas, It has indeed been a delight to read your posts on PSN. What PSN has lacked is someone truly knowledgeable about seismic design. I=92m a hard core instrument freak and inventor myself, and am quite interested in this topic right now. But there is no substitute for someon= e like yourself, conversant with the decades of engineering experience that have been incorporated into commercial products. Incidently I would describe your vertical as a straight-forward hack closely along Streckeis= en (sic-is that the name of that thing?) lines. Let me describe my current understanding of some of the principles of seismic design and then maybe you can correct any misimpressions. Apparently, one general principle with verticals is to be certain the mas= s moves along only one axis-has one degree of freedom. This is the point of the crossed hinge, which effectively defines a pivot axis, as a knife edg= e would do. But there are other ways to do the job. If we suspend a weight from a hacksaw blade clamped in a vise so as to be= nd the top of the blade over horizontal and then suspend a four ounce lead weight from a link of copper wire from the hole in the end of the blade, = we get an oscillator with a period of a second and the oscillations may take twenty minutes to die down-- a very high Q system with a long distance of vertical travel.=20 Easy to set up for one thing--I did it just last night and recorded the results with a DATAQ, because it was simple to rig up and I was curious. For detection I use a phototransistor in close proximity to an LED and chopped by an aluminum flag glued on the bottom of the weight. Such a detector is DC and has nanometer resolution-handy technique.=20 The thing is supersensitive to 1 sec jolts as you would imagine and prett= y useless as a seismometer because of the high Q and lack of damping in the described form. If I should turn this into a useful seismometer, my first step would be to kill the unwanted degrees of freedom by stretching two very fine horizontal nylon filaments at right angles and attach then to t= he lead weight to restrict its travel to the vertical axis and induce heavy damping with any sideways modes of mass vibration. I see some on the char= t. In my mind, the most innovative aspect of your instrument is the use of a loudspeaker coil to induce feedback force. Generally speaking, you are miles ahead in the game if you can borrow some well- engineered, mass produced technology to solve your problems. And a loudspeaker is a great fast high power force actuator so far as cost and mechanical characteristics are concerned ( I have used loudspeakers to build little micropumps, but for some reason, their use in this application had not occured to me). The end result should be to impart as least as much force to the mass as the ground shocks deliver null it. I think you say the force should actually be equal to the full weight of the mass. So you should be able t= o apply four ounces of force at least momentarily with your speaker coil to= a four ounce mass like my fishing weight. In other words, small speaker, small weight. And there is some proportion that fits best as you scale the instrument size up or down.=20 Its dangerous to challege an expert such as yourself, but I do not believ= e I agree with your rule of thumb that the product of the mass in kilograms and period should be at least one. In other words, you should typically t= ry to have one kilogram mass and one second period.=20 I am strongly oriented toward trying to reduce the size of the instrument. The constraints of temperature drift and barometric bouyancy encourage small designs. I like to use an electrical feedback thermostatted enclosu= re for similar instruments and its easy to build small hermetic enclosures from gallon jugs I think Black (?) did a paper on a quartz torsion fiber and horizontal beam gravimeter in the 1960=92s. It was an excessively gold-plated force feedback design, but the device was very small and sensitive to seismic shocks. My understanding from reading this and Melton=92s stuff is that t= he theoretical limit on size is the brownian movement of the mass, but that = in reality the limit is much more likely to be too much energy loss from air damping, which is less with larger masses. Melton suggested that the prop= er bottom limit was 100 grams or so because of the difficulty of pulling and maintaining a high vacuum on plastic coated wire!=20 So my conclusion is that tradition has dictated that seismometers are larger than they probably need to be -- and they could be somewhat or maybe a lot smaller without sacrificing much sensitivity. This conclusion is somewhat in line with the conclusion that long period geophones can be filtered to detect teleseismic events, although perhaps with some loss in sensitivity. Has anyone ever filled a geophone with helium or pulled a vacuum on one to cut gas damping losses? I=92m weak on feedback theory, but my reading of your force feedback appr= oach is that you insert a sort of filter between sensor and speaker coil such that it passes three sources of current; first a straight-through signal, second a low pass or integrated response component, and third a different= al response component through a capacitor. I assume this is right? That mean= s if you could get a big enough choke coil as an integrator, you could have just it, a properly sized resistor and a capacitor in parallel in the loo= p and get equivalent results? This seems to me sort of equivalent to a not= ch filter with adjustable parameters. My own quasi-Luddite approach would be to put three potentiometers in series with each path and then twiddle the three pots until the step response showed the best damping and overall best results. I posted the details of one such force feedback circuit, that works in some cases, recently. I=92m a seat of the pants analog designer, weak on the mathemat= ical side--I=92ve never done a Bode plot to compute critical stability criteri= a, but I have a vague understanding of what is going on. Enough for now. If I=92m way off base in any of my notions, I=92d like to= know. You can repost any of my comments or your possible reply as you wish and = as you think appropriate. PS, did you happen so see my super cheap and simple microbariograph desig= n that I posted a few months back? I notice from your web page that you've worked with the commercial versions. --Yours, Roger Baker; Austin, Texas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Francesco Subject: MAJOR QUAKE IN CENTRAL MEDITERRANEAN SEA Date: Sat, 10 Jan 1998 21:55:05 +0100 Hi guys, Date: 090198 19.21 UTC Preliminary Locate and Mag: 1000 km se from Ancona-Italy: SOUTHERN GREECE - Mb: =>5.5 Registered by all stations of ITALIAN SEISMIC INTEGRATED NETWORK Greetings to all Francesco FRANCESCO NUCERA OSIMO - Ancona - ITALY Lat. 43 29" E - Long. 13 29" E _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: meredith lamb Subject: Trading Post & Larry C's web page donation Date: Sat, 10 Jan 1998 13:54:36 -0700 Hi everyone, Being as I initiated the trading post thought; I feel compelled to respond to Larry Cochranes generious web page offering response. To lay the facts on the line...however, I have as much web page experience as frogs hair is obvious....zero zilch to be exact. Moreover, I don't have the faintest idea what would be involved...unless I delve into this Netscape program which may or may not be adequate?? The manual I have jumps like a frog in subject change. I think they presume everyone is a computer geek already :>) Hey...I can press the wrong button REAL well! I feel strongly about the equipment issue as being the most frustrating parts of this avocation. This is...one of the rarest hobbys there is, and the commercial prices reflect it. Even home brew (all kinds), requires the mental approach of an engineer (all kinds), and compensating green (much) to evolve something that works, let alone work good, or best of all to be reliable & good for a long time (rare). An individual has to be a scavenger to pick the brains and castoffs of others to have some success, let alone what they can learn along the way. Nothing wrong with this, we all do it, and sometimes some of us,.... get the thrill of being asked for our expertise. I can remember my own start (too many years ago), as being somewhat of a....collecting the hairs of a frog into something substantial....mostly the evaporation of fried electronics....due to the lack of funds for more newer components (I hate old capacitors that bang). Hence, .....there is a world of people interested in this, but money controls and limits and often forces an end to their interests. But.......if people have a web page to check...there maybe a piece that helps...may be not....BUT, maybe it offers a glimmer of hope for their precious interests with the page just being there. Pieces & parts seem to be the rule of most of us...one here and one there...mostly scarce or too high priced, BUT MAYBE THERE ON THE WEB PAGE. I carry on don't I? Anyway...being things as they are and with my limitations, unless someone has more computer experience with web page stuff...I will have to decline any kind of consideration as a volunteer...unless you all want to wait a long time and wait for me to gain (any) web page knowledge. GPF's seem to love me...(this is normal?) So....for now...does anybody have the experience..and is willing to do this for the rest of us? Thanks, Meredith Lamb _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Mike Lozano Subject: Re: Trading Post & Larry C's web page donation Date: Fri, 09 Jan 1998 22:33:12 -0600 Hi Meredith & the bunch, Like you, I don't have a much experience with maintaining a Web page, much less a Web site, but I'm willing to learn. I have PageMill (which I'm trying to learn) & PhotoShop 4 (which I use regularly). Since I cast the first stones with a vacuum pump and packet telemetry system which I haven't had any response to, although I'd love to trade them for almost any kind of seismo equipment, I'm going to open my mouth to volunteer to help with a trade page. I someone has the room to host a page, I'll contribute updating and artworking in return for all the stuff I've learned about this fascinating hobby by just 'reading the mail'. How 'bout it? Mike Lozano. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: meredith lamb Subject: Karl Cunningham & NIC circuit Date: Sat, 10 Jan 1998 15:14:41 -0700 Karl, In your 1/9/98 msg re: 4.5hz equalizer about a NIC op amp, you had a VERY interesting mention of a previous circuit you had tried out and thought it may have some merit for a seismo FB circuit. I'am very interested in learning or getting more info on that specific circuit. It sounds just too good to pass by! It maybe difficult temp wise, but with the few parts mentioned, it could be much more reliable over time because of that. Any availability of more info? Thanks, Meredith Lamb _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Stephen Caruso Subject: Re: China quake, bad news Date: Sat, 10 Jan 1998 19:11:36 -0500 (EST) It is a terrible tragedy for those involved. The brighter side is that it was predicted according to the wire service several days ago, but only with a large window into the future. I read the news after getting online at 730am est and the wire report said it happenned at 0323gmt That would have made it an hour later then when I read the report? STEPHEN CARUSO CET KB8UGH "Coincidence is a shortsighted mental delusion" _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Seisguy Subject: Fwd: Quakes Rattle Sicilian Volcano Date: Sat, 10 Jan 1998 21:42:36 EST For those of you interested...... Mike 
Quakes Rattle Sicilian Volcano


.c The Associated
Press


 CATANIA, Sicily (AP) - A series of earthquakes rattling Mount Etna raised
concerns Saturday that the volcano in eastern Sicily might erupt.

``Etna is experiencing a serious enough seismic crisis,'' said vulcanologist
and Civil Defense official Franco Barberi. ``Now we're looking to see if it's
moving toward a true eruption.''

Etna last had a major eruption six years ago. Farm villages stud the volcano's
slopes, and skiers in winter enjoy the mountain snow.

Of the several quakes that began rattling Etna's slopes on Friday evening, the
strongest happened Saturday morning, reaching a preliminary magnitude of 3.8.
A quake of magnitude 2.5 to 3 is the smallest generally felt by people.

No plans to evacuate were announced.

AP-NY-01-10-98 2118EST


 Copyright 1997 The Associated
Press.  The information  contained in the AP news report may not be published,
broadcast, rewritten or otherwise distributed without  prior written authority
of The Associated Press. 


 

To edit your profile, go to keyword NewsProfiles.
For all of today's news, go to keyword News.
From: barry lotz Subject: .WAV files Date: Sat, 10 Jan 1998 09:19:34 -0800 Hi all Does anyone know of a DOS or WIN3.1 program that will perform an FFT on a sound (.WAV) file? If not how about one that will save the file as ascii numbers (.dat or .txt) file? Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Norman Davis WB6SHI Subject: Re: .WAV files Date: Sat, 10 Jan 1998 20:33:48 -0800 At 09:19 AM 1/10/98 -0800, you wrote: >Hi all > Does anyone know of a DOS or WIN3.1 program that will perform an FFT >on a sound (.WAV) file? If not how about one that will save the file as >ascii numbers (.dat or .txt) file? Santis does. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Roger Baker Subject: Mis-posting happens! Date: Sat, 10 Jan 1998 23:38:11 -0600 Whoops, Sorry Folks! I didn't mean to post my comments directed to Sean-Thomas to everyone else on this list, as may have been apparent. But no harm done and it may have been of some technical interest to others. My apology. --Yours, Roger baker _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: kathy mortensen Subject: Re: Mis-posting happens! Date: Sat, 10 Jan 1998 22:08:12 -0700 Roger Baker wrote: > > Whoops, > Sorry Folks! I didn't mean to post my comments directed to > Sean-Thomas to everyone else on this list, as may have been apparent. But > no harm done and it may have been of some technical interest to others. My > apology. > > --Yours, Roger > baker > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L No apology needed here, I hope he comments to the PSN as I am very interested in his projects. It's refreshing to find people willing to share their experiences without a price tag. also, I'm glad to see others using a DATAQ!! While I'm at it, my detector and DATAQ logger recorded the Guatemala (6.4) quake at 00:27:01 PST add approx. 5 sec. for a slow computer clock. SKM My loc. Lat. 38.828 N Lon. 120.978 W _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Roseberry Subject: Re: .WAV files Date: Sun, 11 Jan 1998 00:14:57 -0600 Barry: Try the following URL: http://www-pw.physics.uiowa.edu/mcgreevy/ This page is by a researcher (Stephen P. McGreevy) who records audio-band natural rf, then "listens" to them. Near the bottom of the above referenced page, you will find a link for downloading something called "GRAM23.ZIP"; an explanatory paragraph is reproduced below: GRAM23.ZIP, 33333 bytes You can download SPECTROGRAM 2.3, a freeware Spectrogram program written by R. S. Horne. This spectrogram program plots frequency- versus-time of digital audio recordings. A sound card is required, as this program will not play WAV files using the Windows 3.1x PC-Speaker Driver (as will Sound Recorder). Contains two files: GRAM23.EXE and README.TXT. Lets you save the spectrogram display to a *.bmp file for viewing with Paint Brush. You can also Paste screen prints of the maximized Spectrogram 2.3 window into Word 6.0 or other graphics capable word-processors. Version 2.3 has been improved over version 2.2, allowing for unlimited-length files and also improved bitmap image creation. I used this program about a year ago and found it quite adequate for my needs; it has a very nice user interface, as well. It may serve your needs as well. As they say: you mileage may vary ... Regards, Michael J. Roseberry Fort Worth, Texas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: WAV FFT Date: Sat, 10 Jan 1998 12:04:07 -0800 Michael,Rick&Norman Thanks for your help. I can see many productive hours making use of SANTIS & GRAM32 and WAV files. Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: W6JRF Subject: Re: Mis-posting happens! Date: Sun, 11 Jan 1998 04:32:43 EST I concur with mortskm, no apology needed here either. I found your posting so interesting, I printed it out for my paper archive. While I don't have any equipment as of yet, I know all the info I can gather now will save me time, trouble and that all important factor, MONEY! when I finally do get going on this fascinating pursuit. Keep the info coming. Thanks. Bob (W6JRF @ AOL.COM) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Francesco Subject: Re: Fwd: Quakes Rattle Sicilian Volcano Date: Sun, 11 Jan 1998 11:39:41 +0100 The swarm is still in action. It have been registered around 100 events with MG<= 3.0 The last eruption of the Etna Volcano has happened 6 years, with serious damages. The actual crisis is initiate in the month of December with repeated harmonic shivers and some shake among 3.3/ 4.0 Mg. These elements do retain that an eruption is possible and liable, but of sure there are not such elements that could do retain that a big eruption will be audited. The recent epicenter has located at 3 km of depth in the zone of north/ west of the mountain, then not in the more dangerous zone that is the crater of north/east. The events have followed from the Institute of Vulcanologia of Catania, from the Observatory of Acireale and from our station of Siracusa of ITALIAN SEISMIC SPERIMENTAL NETWORK For more details, contact us. Greetings At 21.42 10/01/98 EST, you wrote: >For those of you interested...... > >Mike >From: AOL News >Return-path: >Subject: Quakes Rattle Sicilian Volcano >Date: Sat, 10 Jan 1998 21:22:21 EST >Organization: AOL (http://www.aol.com) >Content-type: text/plain; charset=US-ASCII >Content-transfer-encoding: 7bit > >
Quakes Rattle Sicilian Volcano
>
>
.c The Associated
>Press

>
> CATANIA, Sicily (AP) - A series of earthquakes rattling Mount Etna raised
>concerns Saturday that the volcano in eastern Sicily might erupt.
>
>``Etna is experiencing a serious enough seismic crisis,'' said vulcanologist
>and Civil Defense official Franco Barberi. ``Now we're looking to see if it's
>moving toward a true eruption.''
>
>Etna last had a major eruption six years ago. Farm villages stud the
volcano's
>slopes, and skiers in winter enjoy the mountain snow.
>
>Of the several quakes that began rattling Etna's slopes on Friday evening,
the
>strongest happened Saturday morning, reaching a preliminary magnitude of 3.8.
>A quake of magnitude 2.5 to 3 is the smallest generally felt by people.
>
>No plans to evacuate were announced.
>
>AP-NY-01-10-98 2118EST
>
>
 Copyright 1997 The Associated
>Press.  The information  contained in the AP news report may not be
published,
>broadcast, rewritten or otherwise distributed without  prior written
authority
>of The Associated Press. 

>
> 
>
>To edit your profile, go to keyword HREF="aol://1722:NewsProfiles">NewsProfiles.
>For all of today's news, go to keyword HREF="aol://1722:News">News.
> FRANCESCO NUCERA OSIMO - Ancona - ITALY Lat. 43 29" E - Long. 13 29" E _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: wizard@......... (Rick Jerome) Subject: Re: .WAV files Date: Sun, 11 Jan 1998 07:48:03 -0800 At 12:14 AM 1/11/98 -0600, you wrote: >Barry: > >Try the following URL: http://www-pw.physics.uiowa.edu/mcgreevy/ > I have been using Gram32 to watch the Seismo information transmitted on VHF from the USGS and DWR. It works quite well for non-critical viewing. Just run it when I'm in the shop. The filtering features allow you to view a single channel. Lots of nice features. I highly recommend it. DATAQ software will also view wave files. You just need to input the correct information in the import program. You will see some incorrect data at the beginning of the file. That data is the header information. You can select a different portion of the wave form for FFT. It also does inverse FFT after filtering. I downloaded it from DATAQ. ------------------------- Michael D wizard@......... N6EGQ Tuolumne, CA ------------------------- "With our ears may we hear what is good." Mundaka _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Bob Thomasson <102073.3346@..............> Subject: Re: .WAV files Date: Sun, 11 Jan 1998 10:53:33 -0500 There is also a fairly elaborate 30 day free trial FFT program at www.telebyte.com/pioneer. It looks to be very interesting. I downloaded it, but the 30 clock expir= ed before I got around to really experimenting much with it. Also, don't know the cost if you want to keep it after 30 days - I think it's $300+ Regards, Bob _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: .WAV files Date: Sat, 10 Jan 1998 22:07:54 -0800 Rick I tried Gram32.I like it. It's small and I have been looking for a program that produces a spectrogram. Do you or anyone else know what the PCM or WAV format is? I always wanted to review recorded quakes this way (without writing the program myself). I would like to adapt some of my recorded events for spectrogram viewing. Barry Rick Jerome wrote: > > At 12:14 AM 1/11/98 -0600, you wrote: > >Barry: > > > >Try the following URL: http://www-pw.physics.uiowa.edu/mcgreevy/ > > > I have been using Gram32 to watch the Seismo information transmitted on VHF > from the USGS and DWR. It works quite well for non-critical viewing. Just > run it when I'm in the shop. The filtering features allow you to view a > single channel. Lots of nice features. I highly recommend it. > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jim Hannon Subject: Re: .WAV files Date: Sun, 11 Jan 1998 12:07:11 -0600 barry lotz wrote: > > Rick > I tried Gram32.I like it. It's small and I have been looking for a > program that produces a spectrogram. Do you or anyone else know what the > PCM or WAV format is? I always wanted to review recorded quakes this way > (without writing the program myself). I would like to adapt some of my > recorded events for spectrogram viewing. > Barry You might want to look at http://www.wotsit.demon.co.uk/ for file formats. I have succesfully input PSN format files into CoolEdit by telling it the file was a raw 16 bit binary file and editing off the header. But sometimes it gets a byte off and doesn't work. -- Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N 91,39.26W WB0TXL _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: VBB Seismometers Date: Sun, 11 Jan 1998 15:12:43 -0600 (CST) Roger & co, A few comments on your comments and questions, which seemed to be an inquiry about why I came up with the "STM-8" sensor. Re the reference to the Strecheisen "STS-1" broadband sensor: I wouldn't say that my sensor has any special relation to it, because leaf-spring sensors have been experimented with for years. And feedback concepts have been applied to overcome the non-linearity of many systems, especially gravimeters. The STS-1 ideas have been described in some detail in the journals. With a response to 360 seconds, is the choice of the world for high-gain, broadband sites. But it is VERY expensive. Guralp Systems of England makes a similar line of compact wideband units at about 1/3 the period and price, but still more than a new car. And Strecheisen also makes a clever compact 3-component 100-second unit, the STS-2, that is very useful for most sites, but still cost gt. $10k. ("clever" because it uses three identical sensors tilted at 45 deg. arranged 120 deg, and electronically summed for vertical and two horizontal outputs). I have been following the development of these sensors for years, and have watched the competition force the performance and price up. THe main performance problem is temperature stability and the noise floor. The USGS lab at Albuquerque has sort of "defined" the noise battle by establishing their "NLNM" model in 1993. ("Observations a and Modeling of Seismic Background Noise", by Jon Peterson, USGS open file report 93-322). In a nutshell, they plotted the PSD (Power Spectral Density) of the quietest data from all the broadband sites around the world, and drew a line under it to represent the "inherent" noise of the earth. So all the instrument makers are trying to show that the self-noise of their sensor is less thatn the NLNM. (BTW, the report "featured" my station CCM in the cavern in the Ozarks because of its' quietness AND susceptibility to barometric noise). You can see the shape of the noise models in my noise study figures when I get them scanned to the web page (maybe tomorrow). But my interest has been a concern for the cost and avaliability of broadband data. The basics of the sensor just aren't that complicated. Once I had a good mathematical model of the transfer function (that properly verified the response of the commercial units with what I knew or could surmise of their physical parameters), I started to look at retrofitting existing mechanisms for broadband response. A major success has been running an old WWNSS long-period vertical at 600 seconds for our display seismograph. The problem with most verticals is the coil spring, which rings without damping; the lateral ringing mode actually shortens the spring, raising the mass in the broadband configuration. So we get one-sided bumps when classes change and the students romp down the stairs (the vault is under the stairs). So I started to evaluate leaf-spring configurations like the available clamped arrangements and realized what a headache it was. Then I found that a flexured suspension avoided all the problems of a clamped spring, and made a seismometer out of it last April. I had already found that the open construction of the VRDT allowed lots of forgiveness in the lateral movement of the boom/mass/coil for large mechanisms; it is only sensitive in one axis. And I had been looking at speakers as seismometers, but the stiff compliance of their suspensions (resonance at 30hz) makes a broadband response difficult. So separating the coil from the magnet was the next step, but brought up the problem that the length of the boom controls the arc of the movement of the coil in the magnet gap; with a 12" boom, it is about 3mm, which is actually plenty for a fedback system; it just takes patience to set up. This is the major constraint on the size of this current arrangement; it would be nice it it all would fit inside a pressure-cooker for protection from barometric noise. Pressure contaiment is used for all the commercial units, but only the STS-1 is actually evacuated. Evacuation makes the baseplate a barometer; the STS-1 has a very thick glass plate that has to be vacuum-grouted to the cement pier surface. Generally a pressure tight case is used, such that pressure CHANGES are reduced, and designed so the base does not flex. We have a continuously recording gravimeter with such a case; you have to vent the cover to open it if the barometer has gone up. Regarding intrinsic damping by air in the container: it is a well known parameter called Bo (actually Beta), and is used to calculate the effective damping. Like for the L4-C, Bo is 0.28; if you want critical damping at 0.7, you need to calculate electrical damping (via the shunt resistor) to contribute (0.7 - 0.28) or 0.41. Regarding the size of sensors: the literature is full of articles on the tradeoff of size vs sensitivity vs self noise. Smaller size can fit into a borehole away from surface noise is the self-noise is controlled. A larger mass raises the Q (quality factor) nicely: my 600-second LP has a mass of 11kg and a period of 15 seconds, so it doesn't show much wind noise; its' containment is a box. But the homemade in my basement here shows a bump when there is enough wind to ring the chimes outside. Regarding the feedback system. I must again emphasize that it is NOT an arrangement of filters of any sort. The three feedback paths EACH provide a characteristic force on the mass based on the information (voltage) from the displacement transducer. Where F=m*a, the result is three characteristic accelerations that shape a linear response that is described by the physics of the terms of the transfer function, which defines the voltage output per input of ground acceleration. Multiplying the acceleration response through by omega (Vel = A *s; s = j*omega) gives the flat velocity response as shown in figure 2. If any of the feedback paths dominate or are missing, the response "blows up", "goes ballistic", or whatever, or is unstable and an oscillator. This is also why the contribution of EACH feedback path is a CURRENT that MUST flow through the force coil. Any modification of this current path makes this concept and transfer function void. It is important to note that WITHOUT the feedback, the displacement detector output is just that, and useful for centering the boom; when, and ONLY when, the feedback is connected, it BECOMES the full broadband output. I guess that MY most important point is that there are endless variations on making something to record ground motion. But to have any scientific usefulness, we cannot just fiddle with hardware and electronics until something "looks" right. We need CALIBRATED instruments, with a stable and reproducible response, recording moderate size events in a digital mode such that the data can be retrived or sent to some collection point in a standard format. And to get calibrated data, we must know exactly how the sensor works, and be able to verify it at will (see fig 12; also the new abstract I have submitted for the March SSA meeting). And a sensor with a broadband response will record the quake in the next county as well as the quake in Tibet without the need of multiple instruments (albeit at different sample rates). I assume that the PSN does want to contribute to the scientific data base with more than just phase arrival times: seismology is in great need for full waveforms (esp. 3-component) for ground motion, attenuation, and tomographic studies. As extensive as "professional" networks are, they do not have stations down in (eg) the inhabited valleys of California (where we really DO need ground motion data), or in every 100x100km area of the world to do tomographic studies of the interior of the earth (a method like a CAT scan that uses a single large quake (eg in Tibet) as the signal source and looks at how the earth modifies the waveform over all possible paths to all possible receivers ie. seismographs). A global network of personal and school broadband seismographs would significantly contribute to this. I hope that all this addresses your interests. Regards, Sean-Thomas St. Louis University _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: wizard@......... (Rick Jerome) Subject: Re: .WAV files Date: Sun, 11 Jan 1998 14:07:05 -0800 >You might want to look at http://www.wotsit.demon.co.uk/ for file >formats. > >I have succesfully input PSN format files into CoolEdit by telling it >the file was a raw 16 bit binary file and editing off the header. But >sometimes it gets a byte off and doesn't work. >-- >Jim Hannon Kind of neat to re-sample the quake and listen to it. Like the FFT display and filtering. ------------------------- Michael D wizard@......... N6EGQ Tuolumne, CA ------------------------- "With our ears may we hear what is good." Mundaka _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: .WAV files Date: Sun, 11 Jan 1998 03:47:03 -0800 Yeh I agree! I set the sampling frequency at 1000x the real sampling rate so you can look at real frequencies and hear it also. It is also neat to look at a scanner file for carrier frequencies. I'm looking for USGS stations near me. Barry Rick Jerome wrote: > > >You might want to look at http://www.wotsit.demon.co.uk/ for file > >formats. > > > >I have succesfully input PSN format files into CoolEdit by telling it > >the file was a raw 16 bit binary file and editing off the header. But > >sometimes it gets a byte off and doesn't work. > >-- > >Jim Hannon > > Kind of neat to re-sample the quake and listen to it. Like the FFT display > and filtering. > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Dewayne (n0ssy) & Linda (n0uqf) Hill" Subject: Meteorite Impact in Denver, CO. Date: Sun, 11 Jan 1998 23:06:00 +0000 I heard on the local news that a meteorite impacted in the Denver area last night. Does anyone have any info on this? Regards, Dewayne Hill _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Al Allworth" Subject: STM-8 sensor Date: Sun, 11 Jan 1998 15:16:20 -0800 S-T Morrissey and PSN I have had more time recently to go over the design of the STM-8 and try to understand how it works. I work a little differently than some people in analyzing something like this. I have to understand how it works before I can see the significience of the numbers. Others get the "how it works"part from the numbers. I'll describe how I think it works and see if I am comming close to reality. In some fedback sensors the feedback removes (almost) all motion from the boom and the various output signals are derived from the feedback signal that is the drive to maintain the boom position. It appears that in the STM-8 this is completely different and the whole purpose of the feedback is to interact with the existing parameters ie: natural period, mass, inherant damping, frequency response, etc to produce suitable new parameters to provide the needed frequency response, lower period, damping, and sensitivity for a more useful seismometer. Since the feedback transducer is also a powerful generator, its dynamics interact with the three feedback networks so that they not only modify the effect of the feedback on the transducer but also have a loading effect on the transducer's output as a generator. This is why the signals can't be summed in an op-amp and then applied to a higher resistance feedback coil. Have I come close? In regards to the L4: Is your mailing address in your web page OK to send a SASE for the data sheets on the L4? _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jim Hannon Subject: Re: VBB Seismometers Date: Sun, 11 Jan 1998 17:21:49 -0600 S-T Morrissey wrote: > And Strecheisen also makes a clever > compact 3-component 100-second unit, the STS-2, that is very useful > for most sites, but still cost gt. $10k. ("clever" because it uses > three identical sensors tilted at 45 deg. arranged 120 deg, and > electronically summed for vertical and two horizontal outputs). > > Sean-Thomas, This is the type of 3 axis sensor that I have been working on. According to my calculations the angle with respect to horizontal is 54.73 degrees for an orthogonal arrangment. I plan on doing the axis rotation in software from the sampled data. If the three sensor outputs are A, B and C the equations for the vertical and horizontal outputs are Z= .57735A + .57735B + .57735C X= .81644A - .40822B -.40822C Y= 0A + ..70706B - .70706C I think it is neat because you can use the same design for all three sensors. -- Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N 91,39.26W WB0TXL _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: Re: STM-8 sensor Date: Sun, 11 Jan 1998 18:29:05 -0600 (CST) AL, The mailing list onthe web page is correct. I also think that your concept of the triple feedback is getting to the point. All the elements interact to produce the output. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: triaxial VBB Date: Sun, 11 Jan 1998 18:33:15 -0600 (CST) Jim, The idea definitely has possibilities for the PSN. We can avoid any question of copying the STS-2 by referring to "The symmetrical triaxial seismometer -- its' design for application to long-period seismometry" , by B.S. Melton and B.M. Kirpatrick, BSSA 60, 1970. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: meredith lamb Subject: Re: Meteorite Impact in Denver, CO. Date: Sun, 11 Jan 1998 20:34:02 -0700 Am checking...various meteorite web sites...only indefinite chatter in cosmic chat room....something like there May have been one about 12:10 Am m.s.t., boom, softball size....would not rely on this as definite. No other references found. It's amazing the number of web meteorite sites, but they are generally 6 months out of date. No local paper mention, but think that if it hit at that time, the paper would have been in production. Will check paper tommorrow a.m. The chat room also mentioned washington or Colorado, wonderful indefinite babble, mostly selling and buying. All this reminds of the Greenland one....days pass before anything definite shows up. Gee Whiz! I'am as bad as they are....I've been fixated on football games! Dewayne (n0ssy) & Linda (n0uqf) Hill wrote: > I heard on the local news that a meteorite impacted in the Denver area last > night. > Does anyone have any info on this? > > Regards, > Dewayne Hill > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: watson@................ (Charles Watson) Subject: Re: Meteorite Impact in Denver, CO. Date: Sun, 11 Jan 1998 20:15:30 -0700 Speaking of meteorites et al, I received Walter Alverez's new book" T. rex and the Crater of Doom" for Christmas and finally had some time to sit down and read some of it. Humm..compelling! Ah, that passion of geologic discovery gets me every time. -- ---/---- Charles P. Watson, Consulting Geologist Advanced Geologic Exploration Seismo-Watch / Earthquake Information Services Voice: 702-852-0992 / Fax: 702-852-3226 Office Location: 39.43N 119.71W mailto:watson@................ http://www.seismo-watch.com _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: W6JRF Subject: Re: .WAV files Date: Mon, 12 Jan 1998 01:01:12 EST Rick, since I don't have any seismo equipment at this time, I am very interested in the frequencies you are using to copy the singals from USGS and DWR. Any chances of you posting them here? Thanks. Bob W6JRF@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Al Allworth" Subject: LA Event Date: Sun, 11 Jan 1998 23:31:54 -0800 Heard something about a 4.0 near Panarama City. Not on USGS yet. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: watson@................ (Charles Watson) Subject: Re: LA Event Date: Sun, 11 Jan 1998 23:37:49 -0700 M3.2 - 2 mi ssw of Panorama City. Got a couple felt reports already. -- ---/---- Charles P. Watson, Consulting Geologist Advanced Geologic Exploration Seismo-Watch / Earthquake Information Services Voice: 702-852-0992 / Fax: 702-852-3226 Office Location: 39.43N 119.71W mailto:watson@................ http://www.seismo-watch.com _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: Trading Post & Larry C's web page donation Date: Mon, 12 Jan 1998 00:14:16 -0800 Meredith and Mike, Don't worry about the actual web page construction, that's the easy part. HTML code is nothing more then some simple text commands. If one or both of you can maintain the page I can come up with a template for you guys to use. All you will need to add is the text describing the equipment and maybe a link to a picture if one is available. Since Mike has a web page maker (I use my text editor for my pages) maybe he should be the main contact / maintainer and Meredith could be backup? I guess the next thing to do is too have people submit there equipment / wish list to Mike so he can create the page. Mike, if this is OK why don't you announce it to the list and when you have a page ready all you need to do is send it to me as an attachment and I will place it on my web server. Regards, Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Walt Williams" Subject: Re: LA Event Date: Mon, 12 Jan 1998 01:53:47 +0000 Hello Charles Watson and All, Around 22:30, 98.01.11, (Canoga Park, California, USA) a short (less than a second) violent jolt was 'felt'. Again, in our house we generally 'hear' a loud bang sound just prior to these earth quake events. Best Regards, Walt Williams, 98.01.12 dfheli@.............. Canoga Park, (LA suburb), California USA =================== ------- Forwarded Message Follows ------- Date: Sun, 11 Jan 1998 23:37:49 -0700 From: watson@................ (Charles Watson) Organization: Advanced Geologic Exploration / Seismo-Watch To: PSN-L Mailing List Subject: Re: LA Event Reply-to: PSN-L Mailing List M3.2 - 2 mi ssw of Panorama City. Got a couple felt reports already. -- ---/---- Charles P. Watson, Consulting Geologist Advanced Geologic Exploration Seismo-Watch / Earthquake Information Services Voice: 702-852-0992 / Fax: 702-852-3226 Office Location: 39.43N 119.71W mailto:watson@................ http://www.seismo-watch.com _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Walt Williams" Subject: Audio FFT program uses sound card Date: Mon, 12 Jan 1998 06:50:34 +0000 Hello All, Located on the top of the last page, an interesting Win95 audio frequency FFT program, 'Frequency Analyzer', which uses sound cards can be had: http://www.relisoft.com/freq.html Program which is written by Bartosz Milewski, is distributed with both Win95 binary executable form as well as with C++ source code which can be compiled. MicroSoft VC++ 4.2 can be used to compile the program; a little twiddling is necessary. Program in its present version does not record nor read files, but that feature should be easy to add. Plug a microphone in and observe in 'real-time' both frequency-domain as well as time-domain spectral audio plots. Walt Williams, 98.01.12 dfheli@.............. Canoga Park, (LA suburb), California USA _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Seisguy Subject: Re: LA Event Date: Mon, 12 Jan 1998 10:30:03 EST In a message dated 98-01-12 02:41:31 EST, Charles Watson wrote: > M3.2 - 2 mi ssw of Panorama City. > Got a couple felt reports already. > Was felt solidly in Northridge. It was a real fast shake, but short in duration. Scared the dog. Mike O'Bleness Northridge, CA _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Francesco Subject: CIO-DAS08/JR A/D & EMON Date: Mon, 12 Jan 1998 17:11:03 +0100 Hi guys, I'm installing CIO-DAS08/JR A/D for one of my sensor. It's need that I know the right A/D I/O address for setting Emon compatible software (downloaded from Bob Hammond ftp-side) or if these is automatically recognized by the programm. I want to know too the best setting of software: sample, noise, buffers ecc.ecc. Thank you very much. Regards Francesco Nucera Osimo - Italy Lat.43.29N Long.13.29E _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: meredith lamb Subject: Colo. Springs meteorite Date: Mon, 12 Jan 1998 11:00:53 -0700 Hi Group, Apparently there was a meteor which came down near Colorado Springs, Colorado, about 12:15a.m. 1/11/98. Apparently many witnesses varying from there, to as far away as about 100 miles. Some say their may have been an impact with house vibrations, and then multiple explosions heard. Description variations of bright white to big blue as it passed through the atmosphere and clouds. A security camera in Colorado Springs which caught the light of another meteor in 1995, also caught the moving light reflection of this one. Local authorities are involved in the details of this new one, and hopefully their will be some more news in the ensuing days ahead. Sounds like the ideal Steve Spielberg movie plot...huh? You know that all this meteorite talk conjures up my own story.... When I was about 10 years old (give-take ~ years), and was out playing at night in Sterling, Colorado (northeast Colo); there was suddenly a bright flare like object coming down vertically. The object was almost like a military flare it seemed to take forever to reach the ground...uh...maybe 30 seconds. It really lite up the sky with an intense white light...no sound. Well....it took about 2 weeks of people searching before it was found...just inside Nebraska. The specimen is now in the Denver Museum of Natural History. Most meteors usually travel about 40 to 60 miles per second~,....this one must have been alot slower than that. It weighted (from memory) maybe 10 or so pounds. An iron variety. Naturally my excited story was dismissed by my partents...till the next day. The original location was Denver, which is false, but at the time I rechecked my gram for the rough time slot....just in case I slept thru any sonic boom vibration.....nah!....hard to tell from the gram, what with the China & Guatamala stuff cluttering up the record and no time marks. Too bad I don't have any A/D stuff yet, that would really be interesting to see a spike for the time. Colorado Springs is about 60 miles south of my Denver location. Meredith Lamb P.S., big distant quake rattling chart recorder for the last hour or so. Difficult to concentrate on this msg (I'am teasing of course). _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: wizard@......... (Rick Jerome) Subject: Re: .WAV files Date: Mon, 12 Jan 1998 10:31:38 -0800 >Rick, since I don't have any seismo equipment at this time, I am very >interested in the frequencies you are using to copy the singals from USGS and >DWR. Any chances of you posting them here? Thanks. Bob W6JRF@....... I would be happy to send you the list. It is rather large to post here. I originally got the info from Larry. Am not sure where you live. The main frequencies I use here in central California are... 164.65, 164.845, 163.605, and 217 MHz. The 217 MHz carrier re-transmits at least 6 seismometers from the San Luis area on 217Mhz. The signal is beamed to the CHP office in Merced. It then it re transmitted again by microwave to the Sacramento Department of Water Resources office. I can detect most quakes from Mammoth that are greater than 1.9. This method of quake watching does not really have the accuracy for real science. It is great for "earth watching". I suspect that with some better filtering and a program written just for this purpose would work quite well. Still not bad for a sound card and a free program. I use FFTdsp for long-term monitoring. It has marginal resolution and creates some rather large disk files when saving. There is no way to trigger an event. (Any ideas from any of the software types out there?). There is a small registration fee for this program. http://www.webcom.com/~af9y/#Bullet 5 When working is the office I use GRAM32. It does have very good resolution, filtering, save wave, and save data points. I wish that it was able to trigger a save from an event threshold setting. This is a well written program and is freeware. It is frequently updated. As mentioned in a earlier post, Santis is a great analysis tool. Santis will do fft, wavelets and much more. http://www.physiology.rwth-aachen.de/bs/signal/santis/ ------------------------- Michael D wizard@......... N6EGQ Tuolumne, CA ------------------------- "With our ears may we hear what is good." Mundaka _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Norman Davis WB6SHI Subject: Re: .WAV files Date: Mon, 12 Jan 1998 07:56:39 At 10:07 PM 1/10/98 -0800, you wrote: >Rick > I tried Gram32.I like it. It's small and I have been looking for a >program that produces a spectrogram. Do you or anyone else know what the >PCM or WAV format is? I always wanted to review recorded quakes this way >(without writing the program myself). I would like to adapt some of my >recorded events for spectrogram viewing. I was using it last night. It is 11k sampling rate mono. I like it too and still havn't got it working just right. Norman Davis WB6SHI Email normd@............. Shingle Springs, Ca, USA it ain't local... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Norman Davis WB6SHI Subject: VBB Seismometers schematic Date: Mon, 12 Jan 1998 08:02:43 Sean Was looking at the schematics of the limiting amp from your web page and saw what looks like a typo. Is the dioed bridge shorted on perpose? I have never seen one like that. Norman Davis WB6SHI Email normd@............. Shingle Springs, Ca, USA it ain't local... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Norman Davis WB6SHI Subject: Re: Meteorite Impact in Denver, CO. Date: Mon, 12 Jan 1998 08:21:00 >Am checking...various meteorite web sites...only indefinite chatter in cosmic >chat room....something like there May have been one about 12:10 Am m.s.t., >boom, softball size....would not rely on this as definite. No other >references >found. Dewaine What is the server on the cosmic chat. Norman Davis WB6SHI Email normd@............. Shingle Springs, Ca, USA it ain't local... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: meredith lamb Subject: Add another tool to the S-T seismo? Date: Mon, 12 Jan 1998 12:37:53 -0700 Hi group, This idea came from my brother Robert Lamb in Texas afew days back....however,...I think it was mentioned once in past PSN notes, but not elaborated on thereafter. Simply use a carpenters level as the seismo boom. Most are sturdy with an "I" beam construction and naturally bubble levels which could be used to check the "zero". They come in a huge variety of aluminum, plastic, wood/metal combos, varying lengths, with either open "I" or closed box ends. Weight considerations would dictate a gravitation toward the lighter or thin wall cheapies. The prices of simple aluminum stock compared to cheap levels is inviting for comparison consideration of the wallet. Think about it awhile..... Now.....if there was a way to solder to the carbon in carpenters pencils................. :>) Meredith Lamb _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: meredith lamb Subject: Cosmic Chat Room reference Date: Mon, 12 Jan 1998 12:56:00 -0700 Norman, The cosmic chat room is on http://www.meteoritecentral.com/ Upon opening the above, check on the left, look for the red letter word...Weekly!.... This chat only operates on Sundays from 6 pm Pacific Daylight Time....don't know when it ends. Meredith Lamb _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: Re: VBB Seismometers schematic Date: Mon, 12 Jan 1998 14:16:46 -0600 (CST) Norman, The diode brige is shown with a DOTTED line across it for when no limiting is desired, but the dots turn into a line looking like a short when the drawing is scanned, etc. Thanks for the pointer; I'll try to make sure that important details don't get lost. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: boom structure Date: Mon, 12 Jan 1998 14:23:49 -0600 (CST) Meredith, A point about the boom structure is that it must have relatively small net mass WRT the seis mass, or the Cm (center of mass) moves well away from the force transducer. Your point about rigity, etc, is important, but I manage with a 1" wide x 1/2 deep channel of 1/16" aluminum; a 6 ft length is only a few $$. Also, BTW, I have your SASE, but I haven't had a chance to take a couple of polaroids of the LP vertical for you. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Dennis Eckert" Subject: Re: .WAV files Date: Mon, 12 Jan 1998 12:08:09 -0800 Rick, Re Santis, how does one read the doc files? They have an extension of PS. Any idea what format that is? -- Dennis _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "James M Hannon" Subject: Re: .WAV files Date: Mon, 12 Jan 1998 15:14:02 -0600 Dennis, The .PS extension is a postscript file. You need to copy the file to a postscript capable printer or find a postscript viewer. Jim Hannon deckert7@....... on 01/12/98 02:08:09 PM Please respond to psn-l@............. To: psn-l@............. cc: (bcc: James M Hannon/CedarRapids/Collins/Rockwell) Subject: Re: .WAV files Rick, Re Santis, how does one read the doc files? They have an extension of PS. Any idea what format that is? -- Dennis _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: lahr@.................. Subject: Re: .WAV files Date: Mon, 12 Jan 1998 14:33:04 -0700 (MST) Dennis, A .ps postscript viewer can be found on shareware.com http://search.shareware.com/ Search for gs261ppc.zip JCLahr _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: meredith lamb Subject: Re: boom structure Date: Mon, 12 Jan 1998 14:35:17 -0700 S-T Morrissey wrote: > Meredith, > A point about the boom structure is that it must have relatively > small net mass WRT the seis mass, or the Cm (center of mass) moves > well away from the force transducer. Your point about rigity, etc, > is important, but I manage with a 1" wide x 1/2 deep channel > of 1/16" aluminum; a 6 ft length is only a few $$. > > Also, BTW, I have your SASE, but I haven't had a chance to take > a couple of polaroids of the LP vertical for you. > > Regards, > Sean-Thomas > > Sean-Thomas,... OK and thanks for the reply, it seemed to bean interesting approach with the carpenters level. Is their a crude working ratio of Boom versus Mass weight available or a guesstimate you're aware of? I.e.....boom 1, mass 50, or thereabouts? Like, 50Mass:1Boom weight? Its probably higher, but I don't know. OK on the polaroids of the LP vertical. That will be very helpful as I have no manuel on the vertical. I got it about 25 years ago and had to disassemble it at the time, due to moving and storage and more damage prevention & etc. It turns out after all that time.....I forgot where all the parts go! The LP horizontals are a snap compared to the vertical Sprengnether. The polaroids will help I'am sure, or I can always trapse over to the NEIC branch in Golden and look at the one they have on display cases. They have alot of old timers behind the glass there. If anyone is in Denver area, check them out. The machine work of all of them is wonderful, including the early brass seismometers there. Thanks Sean, Meredith Lamb _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Karl Cunningham Subject: Re: NIC Circuit Date: Mon, 12 Jan 1998 15:07:28 -0800 Meredith -- The negative impedance converter (NIC) is a fairly simple op-amp circuit. I've put a schematic of it at: http://www.jps.net/karlc/nic.gif The schematic says that the two R's must be well matched. In reality, the output impedance is -(Z * R1 / R2), so a fine adjustment of R1 or R2 could allow you to tweak the impedance to just what you want. The idea is to have the coil's resistance (plus lead wire resistance) exactly matched by the negative output impedance of the NIC. If the impedance of the NIC is nearer to zero than the coil, the system will oscillate, so adjust just shy of that. The copper wire in the coil will change resistance with temperature, so it might be good to construct R3 out of copper wire and mount it near the drive coil to compensate. This will also help cancel thermal emf's generated by dissimilar metals associated with resistors. Use as good an op-amp as you can get (chopper stabilized?). You can reduce the bandwidth by putting a capacitor across R2. Use the op-amp's output to feed the a/d. It is proportional to current in the coil, which is proportional to acceleration. Sean-Thomas' post yesterday makes me think that a loudspeaker may not be a very good thing to use by itself due to the damping of its suspension. I'd still try it to see how it works, though. But as he suggests, using the coil and magnet from the loudspeaker would save a lot of work. If you decide to give it a try, let us know how it works. And if you have any questions, please ask. Karl Cunningham La Mesa, CA. PSN station #40 karlc@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Stephen Paul Subject: LA Felt Report Date: Mon, 12 Jan 1998 15:14:31 -0800 Hi All, For anyone who might be interested, last night in the Sherman Oaks hills, we felt the Panorama City quake in a B-I-G way. Sounded initially like someone dropped a boxcar on the house (P, no doubt) followed by 20-25 seconds of vigorous shaking, getting harder and softer, harder and softer, 'til it died out about ten minutes later completely. This no doubt was the sine-like structure of the S. The initial jolt was -very- loud, a BANG resembling a car accident, (more like a semi accident!) probably in the 92-102 ADb power range in amplitude as perceived by us inside the house. I estimate we were 4-6 miles South and 2-3 miles west of the epicenter. Exciting, but grim, a very real reminder of the convulsions we endured in '94. Though this is a Scientifically-oriented forum, I wanted to point out, that long before the science of Plate Tectonics was even postulated; in the twenties and thirties, Edgar Cayce predicted such a sequence as we experienced, i.e. 1. Disturbances in the South Pacific (Vanuatu?), 2. Followed by eruptions and/or disturbances at Etna, 3. Followed by California. Just something to mull over, no? I realize there are things going on all over the globe on a daily basis of some consequence, but I did find it interesting that the most noted sequences roughly followed this pattern... Please, no vegetable or beer can throwing... -- Stephen :^) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: CIO-DAS08/JR A/D & EMON Date: Mon, 12 Jan 1998 05:29:34 -0800 Hi Francesco Most cards have an IO address setting. I use between 300-31F hex (prototype card). With the DAS08/JR if you are using a port I thing you would use the port address (LPT1,LPT2, COM1 etc). Let me know what port you are using and I can check. Barry Francesco wrote: > > Hi guys, > I'm installing CIO-DAS08/JR A/D for one of my sensor. > > It's need that I know the right A/D I/O address for setting Emon compatible > software (downloaded from Bob Hammond ftp-side) > or if these is automatically recognized by the programm. I want to know too > the best setting of software: sample, noise, buffers ecc.ecc. > > Thank you very much. > Regards > Francesco Nucera > Osimo - Italy > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: .WAV files Date: Mon, 12 Jan 1998 05:40:53 -0800 Rick EMON has a threshold setting. I thing there is a parallel port hardware settup for it if you don't have a board. Ted or Steve Hammond know more about the port configuration. I am running EMON with satisfaction. I am also running a Quick Basic trigger program I wrote simultaneously which runs overlapping FFT's and looks for variations from a running average background. I can pick up more than with a simple threshold. Also if the frequencies you mentioned are different than that refered to in Larry's site I would also be interested Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: .WAV files Date: Mon, 12 Jan 1998 05:47:19 -0800 Norman I also like it. The problem I had was that when I used a program called COOLEDIT to save the quake file as a WAV file The amplitude changes. I don't mean simple gain I mean the event looks like it clips. A Mammoth event with distinctive P & S amplitudes come out with similar amplitudes in GRAM32. It looks like maybe it's plotting a log vertical scale.???? Any ideas out there? Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: bob@................. (Bob Hammond (USGS-AVO Geophysicist)) Subject: Re: CIO-DAS08/JR A/D & EMON Date: Mon, 12 Jan 1998 15:46:45 -0900 Francesco, Set your A/D I/O address to 768 as is shown in the emon.opt file: FirstSeismometerAddress = 768 (decimal i/o address) and note the comment Ted Blank put right above the addressing lines which says that most pc i/o addresses are in hex but EMON wants decimal so 300h = 768 decimal. hope this helps, Bob Hammond APSN Fairbanks _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: kathy mortensen Subject: recorded 2 big quakes Date: Mon, 12 Jan 1998 16:55:44 -0700 recorded the 6.2 central Chile quake at 02:26:33 +/- 1 sec. recorded the 6.7 Fiji Islands quake at 08:48:21 +/- 1 sec. SKM Pilot Hill, Calif. USA lat 38.828N lon 120.978W _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Francesco Subject: Re: CIO-DAS08/JR A/D & EMON Date: Tue, 13 Jan 1998 02:12:53 +0100 Hello Barry I have inducted the card in an ISA free slot of my 386PC that coincides to serial port. However, I could induct the card in LPT1 that I don't use for stamp. The standard address of CIODAS08JR is 300 hex. Must I write this address in EMON.OPT lines? There is a problem that I don't succeed to resolve. The problem is that if in EMON.OPT I choose the option "NORMAL" in the line operating mode line of the input data, the program begins to run but it stop immediately ! With the RANDOM option the program is ok, but it don't register the data from the sensor. Give me your evaluation. I thank you so much FRANCESCO NUCERA OSIMO - Ancona - ITALY Lat. 43 29" E - Long. 13 29" E _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: CIO-DAS08/JR A/D & EMON Date: Mon, 12 Jan 1998 06:46:28 -0800 Francesco Bob is right. Try decimal rather than hex. "Normal" is ok. Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: wizard@......... (Rick Jerome) Subject: Re: .WAV files Date: Mon, 12 Jan 1998 17:51:58 -0800 At 12:08 PM 1/12/98 -0800, you wrote: >Re Santis, how does one read the doc files? They have an extension of PS. >Any idea what format that is? You need to download a copy of Ghostview32 version 2.2. It is available from a variety of sources. File to look for is GSVIEW.exe. Can't remember where it was downloaded from. Do remember that it was a confusing maze to find the right version. I suppose I could e-mail it to you if your provider allows large file downloads. ------------------------- Michael D wizard@......... N6EGQ Tuolumne, CA ------------------------- "With our ears may we hear what is good." Mundaka _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: RADIOTEL Subject: Re: CIO-DAS08/JR A/D & EMON Date: Mon, 12 Jan 1998 21:40:47 EST Francisco Nucera: I have the same A/D board and obtainted the specially formatted EMON developed by Ted Blank for Bob Hammond. It is already configured to work with this particular A/D card and uses a First Seismo Address of : 768. It should run right off the bat with this number. Lots of luck Jim Allen Cerritos, California _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Ted Blank Subject: Re: CIO-DAS08/JR A/D & EMON Date: Mon, 12 Jan 1998 19:01:12 -0800 (PST) Francesco, You must enter the address of the card in decimal in the EMON.OPT file. 300 Hex corresponds to 768 decimal. Please try that and tell me if you have any more problems. Regards, Ted > > Hello Barry > > I have inducted the card in an ISA free slot of my 386PC that coincides to > serial port. However, I could induct the card in LPT1 that I don't use for > stamp. > The standard address of CIODAS08JR is 300 hex. Must I write this address in > EMON.OPT lines? > > There is a problem that I don't succeed to resolve. The problem is that if > in EMON.OPT I choose the option "NORMAL" in the line operating mode line > of the input data, the program begins to run but it stop immediately ! With > the RANDOM option the program is ok, but it don't register the data from > the sensor. > > Give me your evaluation. > I thank you so much > > > > FRANCESCO NUCERA > OSIMO - Ancona - > ITALY > > Lat. 43 29" E - Long. 13 29" E > > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jim Hannon Subject: Re: .WAV files Date: Mon, 12 Jan 1998 21:07:25 -0600 barry lotz wrote: > > Norman > I also like it. The problem I had was that when I used a program > called COOLEDIT to save the quake file as a WAV file The amplitude > changes. I don't mean simple gain I mean the event looks like it clips. > A Mammoth event with distinctive P & S amplitudes come out with similar > amplitudes in GRAM32. It looks like maybe it's plotting a log vertical > scale.???? Any ideas out there? > Barry, I think the problem is that the quake file doesn't always have an even number of bytes in the header. This causes the 16 bit data to be read out of byte order. I wrote a simple c program to strip off the header from to quake files before using cooledit. -- Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N 91,39.26W WB0TXL _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: meredith lamb Subject: NIC CIRCUIT Date: Mon, 12 Jan 1998 20:03:59 -0700 Karl Cunningham, Thanks for the reply msg and schematic, and the effort you've given. I think that somewhere down the road of time I'll devote more time to this approach on an experimental basis. I'am definitely weak on electronics, but I think I understand most of your presentation. I think it will be fun to fuss with. I think its obvious that the schematic symbol Z means R3 feed back coil and that -Z means the drive/pickup coil connection to input IC and the opposite -Z coil end to common ground? ...........Yes.....I'am that bad....at electronics. Thanks, Meredith Lamb _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "David A. Nelson" Subject: Re: recorded 2 big quakes Date: Tue, 13 Jan 1998 16:23:55 +1200 At 04:55 PM 1/12/98 -0700, you wrote: >recorded the 6.2 central Chile quake at 02:26:33 +/- 1 sec. >recorded the 6.7 Fiji Islands quake at 08:48:21 +/- 1 sec. >SKM >Pilot Hill, Calif. USA >lat 38.828N lon 120.978W hi kathy , great stuff, just check ur times tho the fiji event was a lot earlier than u stated i presume a typo on ur part..... or u were quoting local times NOTE: if local times they dont mean anything to anyone else around the world. get urself a 24 hr clock and have it set to UTC universal time so the rest of us can make use of ur times otherwise keep up the good work and welcome to the world of amateur seismology 98/01/12 16:36:21 15.64S 179.66W 33.0 6.7Ms A FIJI ISLANDS REGION when u are ready it would be good to get some station setup data from u so i can add u to the map and database of worldwide stations go to http://psn.quake.net/dave/map.htm and below the world map u will find a list of the info i am after for the database copy and paste that list into ur e-mail prog and fill in ur info Many thanks Dave Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson ZL4TBN 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: kathy mortensen Subject: Re: recorded 2 big quakes Date: Mon, 12 Jan 1998 20:18:23 -0700 David A. Nelson wrote: > > At 04:55 PM 1/12/98 -0700, you wrote: > >recorded the 6.2 central Chile quake at 02:26:33 +/- 1 sec. > >recorded the 6.7 Fiji Islands quake at 08:48:21 +/- 1 sec. > >SKM > >Pilot Hill, Calif. USA > >lat 38.828N lon 120.978W > > hi kathy , > great stuff, just check ur times tho the fiji event > was a lot earlier than u stated i presume a typo on ur part..... or u > were quoting local times > > NOTE: if local times they dont mean anything to anyone else around the > world. get urself a 24 hr clock and have it set to UTC universal time > so the rest of us can make use of ur times oops!! Just testing the psn waters and am very interested!! I'll do better as the years go by -- I hope! Thanks for the welcome. But yes the times were local pst. Chile should have been 10:26:33 +/- 1 sec UTC Fiji 16:48:21 +/- 1 sec UTC and maybe +/- a couple more sec until I get a little more experience in reading the wave forms!!! Stephen K. Mortensen (SKM) My wife Kathy sign us up to the server and we just keep it that way. She is involved with disaster preparedness. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: Re: boom structure Date: Mon, 12 Jan 1998 22:39:53 -0600 (CST) Meredith, There is no magic ratio of boom mass wrt main mass. Technically, since we have hinged suspensions, we all have rotational systems, and should be figuring rotational angles and torqes about the hinge, etc. (Fortunatley our displacements and therefore our angles are very small, so we can consider our sensors as simple translational systems, and pick a handy reference point, like the center of the main transducer. The closer that the center of mass of the boom + main mass is to that point, the better our approximations are.) Considering the torques about the hinge: the main mass exerts L*M, where L is the boom length. The boom exerts 0.5*L*B, if the Cm(b) of the boom mass B is at the center of L. So the total torque about the hinge is (L*M + 0.5*L*B) or L*(M + 0.5*B). So if we pick M=450gm and B=100gm (about what the Beta sensor here has), we have a torque of L*500 gm. But this is equivalent to the angular momentum of the whole boom + mass system, wrt its' center of mass, (as if all the mass were at the Cm.) So: Cm * (450 + 100) = L * 500, or Cm = 0.91*L. So theoretically we should have the transducers at 91% of the boom length from the hinge for this example. Fortunately, it is not a big care unless/ until we want to nail the calibration to better than 10%. I determine the effective mass by leveling the boom and then removing the mass, coil, balance weights, etc, and then stacking up brass test weights above the center of the force coil until it is again balanced; then I total up the test weights. I hope this answers your question. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: .WAV files Date: Mon, 12 Jan 1998 11:24:57 -0800 Jim I wrote a Basic program to strip off the 100 byte header. I got the same thing. It was mentioned to run a program called Ghostview. I found it but was reluctant to run it since it uses a fair amount of memory and I'm worried about uninstalling it if I don't like it. Rick- Does it do more than strip the header? Barry Jim Hannon wrote: > Barry, > I think the problem is that the quake file doesn't always have an even > number of bytes in the header. This causes the 16 bit data to be read > out of byte order. I wrote a simple c program to strip off the header > from to quake files before using cooledit. > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "David A. Nelson" Subject: Re: recorded 2 big quakes Date: Tue, 13 Jan 1998 19:21:35 +1200 >oops!! Just testing the psn waters and am very interested!! >I'll do better as the years go by -- I hope! Thanks for the welcome. >But yes the times were local pst. >Chile should have been 10:26:33 +/- 1 sec UTC >Fiji 16:48:21 +/- 1 sec UTC >and maybe +/- a couple more sec until I get a little more experience in >reading the wave forms!!! >Stephen K. Mortensen (SKM) >My wife Kathy sign us up to the server and we just keep it that way. >She is involved with disaster preparedness. Hi Stephen, Thanks for correcting me, pleased to meet u. Dont take this the wrong way but i'm just a little saddened I thought we must have finally had the first lady amateur seismologist joining our group. . of course I welcome all and everyone the more the merrier so to u and Kathy a big hi there. a suggestion on a 24hr clock I procured some factory seconds, oven clocks they are great decent large digitsand reasonablry small in size. because i am also an amateur (ham) radio operator my radio contacts are also logged in UTC Cheers Dave Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson ZL4TBN 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Radio Shack's Radio Controlled Clock Date: Tue, 13 Jan 1998 02:28:32 -0800 Hi Everyone, I thought I would document my experience with the new Radio Controlled Clock that Radio Shack is selling for around $40.00. The clock uses WWVB for its time information and I thought I would buy one to see if it could be used for time keeping with my SDR data logging program. As many of you know my A/D card, and software, currently uses WWV or WWVH to keep the computers time accurate to within a few milliseconds of UTC time. I was hoping the new radio clock would be another way PSN stations in the USA could keep accurate time. The clock has two parts to it. One is the main LCD display and an "antenna" that is about 5 inches long. The two are separated with ~3 feet (1m) of wire. I bought the unit some time in early December, and when I first got it, I could not get it to lock up to the time signal. I tried everywhere in my house, nothing. So I set it up in a high place in my house hoping that it would lock some day. I kept checking every day, again nothing. After about a week of this I was getting pretty discouraged. Then one day, just before Xmas, it locked up. It turns out that the people at NIST, who send out the WWVB signal, increased the power of their transmitter from a whopping 10KW to around 20KW (they will be increasing it to 40KW in a few months) on DEC. 19th. This increase was enough for the clock to lock to the signal. At this point I had something to work with. No need to poke around if I can get it to lock.... So I opened the main unit, like any good electronics nerd will do, to see what I could find. I was expecting to find something that looked like a small radio receiver in it. I didn't see anything that looked like one. I then started probing around with an o-scope to see what I could find. All I could find was some LCD drive signals, nothing that could be easily converted to a time reference for SDR. I then look at the signals around the wire from the antenna assembly. There where 4 wires that terminated on the PC board. They are marked VE+, GND, DCF and PON. With the scope I found that +VE had the + battery voltage (two AAA batteries power the unit for a voltage of around 3 volts) on it. The GND was the - battery side. The PON would be at +3 volts when the unit was not trying to lock to WWVB, and ground if it was using the receiver. And the DCF signal had some sort of "digital" signal on it when PON was at GND. The unit tries to lock onto WWVB every 3 or 4 hours. If it can lock onto the signal, or times out in 5 to 10 minutes it sets the PON signal back to +3v. I then open the "antenna" assembly. It turns out that it has the antenna and a complete receiver in it. The assembly has an ~5 inch farad rod, and a coil wound on it, and a small PC board with a potted IC. Since I didn't know what the format of WWVB was, I did know that it was transmitted at the low freq. of 60khz (not mhz), I did an Internet search and found that it has a one bit per second data rate (see http://www.boulder.nist.gov/timefreq/ for more info on WWV and WWVB). To send the time code the transmitter reduces its power by 10db for 200 milliseconds to signal a binary 0, 500ms for a binary 1 and 800ms for a framing mark. The framing mark is sent every 10 seconds. After locating the antenna/receiver in a good location, the unit is pretty sensitive to the orientation and location, I could see the 1 pps data bits on the DCF wire with the scope when the receiver was on. You can force the unit to try and lock on the time signal by turning the unit off and on again. Since the receiver was located in the antenna assembly, and the main unit turns the receiver on and off, I decided to remove the receiver from the main LCD unit and power it my self. I also came up with a simple circuit that would take the DCF output and drive a digital input port on my A/D card or the PC-Labs 711s card. The following web page has the schematic: http://psn.quake.net/wwvbsdr.html. Rather then power the unit at 3 volts (I didn't have a 3 volt regulator on hand) I tried using +5 volts. It seems to work fine despite the extra 2 volts. I then modified SDR to read the signal from the receiver. Since I already had code that recognized a 800ms top of the minute pulse from WWV, I was able to change the code so it could use the 800 ms framing pulses from WWVB. WWVB sends out two back to back framing pulses, one second before the top of the minute, and another one at the top of the minute. SDR uses the two framing pulse to know when the top of the minute happens and uses this mark to keep the system time accurate. It doesn't seem to work as well as my WWV setup put it was able to keep one of my SDR systems accurate to within +-15ms. I can get better accuracy, +- 5 ms, with my $200+ short-wave receiver tuned to WWV on 5.0 MHZ, and outside antenna, but for $40.00, and a handful of parts, +-15 ms is not to bad. If you would like to try the receiver clock with SDR the first thing to do is get one from Radio Shack and see if you can get it to lock in your location. If you can't get it to lock hopefully you can bring it back. If you can get it to lock then build up the interface circuit (or contact me and I can build one for you) and connect it to the digital input port 0 of my A/D card (pin 32 and one of the digital GND pins) or port 0 of the PC-Labs card. You will also need to contact me for a new version of SDR. Regards, Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jim Hannon Subject: Re: .WAV files Date: Tue, 13 Jan 1998 05:46:20 -0600 barry lotz wrote: > > Jim > I wrote a Basic program to strip off the 100 byte header. I got the > same thing. It was mentioned to run a program called Ghostview. I found > it but was reluctant to run it since it uses a fair amount of memory and > I'm worried about uninstalling it if I don't like it. Rick- Does it do > more than strip the header? > Barry > Berry, I think the subject line got used for two discussions. GhostView is a program for viewing .PS or postscript files. This type of file is sometimes used to distribute documentation as it is postscript printer ready. Problem is not everyone has a postscript printer. This has nothing to do with quake files. Try stripping off 101 bytes and see what happens. -- Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N 91,39.26W WB0TXL _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Ted Blank Subject: EMON V7 available on PSN web site Date: Tue, 13 Jan 1998 06:01:03 -0800 (PST) EMON V7.0 is now available on the PSN website. The list of enhancements include - Support for Larry's PSN-ADC board (both 12 and 16 bit versions) - Support for Computer Boards CIO-DAS08Jr/16-AO 16-bit A/D card - Fix for a bug where data was not saved in the middle of a large event In addition, a complete set of documentation is now available in MS Word format (saved as a Word 2.0 file), and also in Windows WRI as well as text format. (So rry, the text format file won't have the screen captures showing how the progrma s work). If you download the EMON 7.0 package you will get EMON, QUAKEVU, all the utility programs, but the documentation files are packaged separately for folks who don 't want / need them. I've also packaged the QUAKEVU code / documentation by itself for folks who are just displaying files and don't want all the data collection code. The separate QUAKEVU package is also available on the PSN web site. My thanks to Larry for putting up the code. Let me know if you have any problems/questions. Happy quake hunting. Ted _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Roger Sorensen Subject: Re: CIO-DAS08/JR A/D & EMON Date: Tue, 13 Jan 1998 07:28:33 -0800 RADIOTEL wrote: > > Francisco Nucera: I have the same A/D board and obtainted the specially > formatted EMON developed by Ted Blank for Bob Hammond. It is already > configured to work with this particular A/D card and uses a First Seismo > Address of : 768. It should run right off the bat with this number. > Lots of luck > Jim Allen > Cerritos, California > Make sure you have the EMON version that runs with the DAS08JR (from Bob). If you don't, EMON will start up, flash the main screen for a split second, and then shut down. If you watch very closely in the upper left hand corner of the screen you'll see a message that says 11 is an invalid type. (11 being the DAS08JR). It's pretty easy to get multiple versions mixed up (I know, because I did that last night ;-) Roger Sorensen Chatsworth, CA USA _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Karl Cunningham Subject: Re: NIC CIRCUIT Date: Tue, 13 Jan 1998 08:24:24 -0800 Meredeth -- You are correct that the drive/pickup coil attaches to the -Z terminal of the circuit, and R3 is a dummy resistor of the same resistance as the coil. -- Karl At 08:03 PM 1/12/98 -0700, you wrote: >I think its obvious that the schematic symbol Z means R3 feed back >coil and that -Z means the drive/pickup coil connection to input IC >and the opposite -Z coil end to common ground? _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "James M Hannon" Subject: Re: Radio Shack's Radio Controlled Clock Date: Tue, 13 Jan 1998 10:43:08 -0600 Larry, This is great! It is a little late maybe but the chip in the Radio Shack receiver part of the clock is made by Temic Semiconductors part number U4223B http://www.temic.de/semi/hn/broadcas/radiocon.htm is a link to the data sheet on the chip. The chip costs about $2.50 each but it maybe hard to get under the minimum order. Running the chip on 5 volts may be pushing it. The data sheet gives 5.25 V as the absolute max . There are a number of time code transmitters in Europe that are more powerfull than WWVB and radio controlled clocks and even wrist watches are very popular there. cochrane@.............. on 01/13/98 04:28:32 AM Please respond to psn-l@............. To: psn-l@............. cc: (bcc: James M Hannon/CedarRapids/Collins/Rockwell) Subject: Radio Shack's Radio Controlled Clock Hi Everyone, I thought I would document my experience with the new Radio Controlled Clock that Radio Shack is selling for around $40.00. The clock uses WWVB for its time information and I thought I would buy one to see if it could be used for time keeping with my SDR data logging program. As many of you know my A/D card, and software, currently uses WWV or WWVH to keep the computers time accurate to within a few milliseconds of UTC time. I was hoping the new radio clock would be another way PSN stations in the USA could keep accurate time. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Dennis Eckert" Subject: Re: .WAV files Date: Tue, 13 Jan 1998 10:03:50 -0800 Thanks for the offer....I downloaded it, and now just have to try it out. Dennis Eckert KB7ST (Amateur Radio Operator) Flies Standard Cirrus sailplane (SV) In Western & Eastern Washington ICQ 4324132 -----Original Message----- From: Rick Jerome To: PSN-L Mailing List Date: Monday, January 12, 1998 7:52 PM Subject: Re: .WAV files >At 12:08 PM 1/12/98 -0800, you wrote: >>Re Santis, how does one read the doc files? They have an extension of PS. >>Any idea what format that is? > >You need to download a copy of Ghostview32 version 2.2. It is available >from a variety of sources. File to look for is GSVIEW.exe. Can't remember >where it was downloaded from. Do remember that it was a confusing maze to >find the right version. I suppose I could e-mail it to you if your >provider allows large file downloads. >------------------------- > >Michael D > >wizard@......... > >N6EGQ > >Tuolumne, CA > >------------------------- > >"With our ears may we hear what is good." > Mundaka > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: kathy mortensen Subject: Re: recorded 2 big quakes Date: Tue, 13 Jan 1998 10:39:30 -0700 David A. Nelson wrote: > > >oops!! Just testing the psn waters and am very interested!! > >I'll do better as the years go by -- I hope! Thanks for the welcome. > >But yes the times were local pst. > >Chile should have been 10:26:33 +/- 1 sec UTC > >Fiji 16:48:21 +/- 1 sec UTC > >and maybe +/- a couple more sec until I get a little more experience in > >reading the wave forms!!! > >Stephen K. Mortensen (SKM) > >My wife Kathy sign us up to the server and we just keep it that way. > >She is involved with disaster preparedness. > > Hi Stephen, > Thanks for correcting me, pleased to meet u. Dont > take this the wrong way but i'm just a little saddened I thought we > must have finally had the first lady amateur seismologist joining our group. > . of course I welcome all and everyone the more the merrier so to > u and Kathy a big hi there. a suggestion on a 24hr clock I procured > some factory seconds, oven clocks they are great decent large digitsand > reasonablry small in size. > > because i am also an amateur (ham) radio operator my radio contacts are > also logged in UTC > > Cheers > Dave > > Co-ordinator: > New Zealand > Public Seismic Network > Dave A. Nelson ZL4TBN > 24 Jensen St., > Green Is., Dunedin, > South Is.. New Zealand. > > http://psn.quake.net/dave/home.htm > > IF there indeed are other parallel universes... I can now rest in the > knowledge, that in at least one of them, I am filthy rich and drive a red > Ferrari > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L NO LADY SEISMOLOGISTS??? NOW I'M SAD I use a windows 3.1 and 95 program called ATOMIC CLOCK by PARSONS TECHNOLOGY http://www.parsonstech.com to keep track of time as well as set my computer clock by modem. It's a cute little program and was able to pick it up at compusa (I think) for about $15.00. It was in their clearance bin!! SKM _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: Purchasing Seismograph Date: Tue, 13 Jan 1998 14:41:06 -0700 John- In terms of putting together a seismograph for your own use at home, the best source of info I know is the Public Seismic Network (PSN): http://psn.quake.net Otherwise, here is a partial list of homepages of manufacturers of portable autonomous digital seismographs (PADS): http://www.reftek.com/ http://www.kinemetrics.com/index.html http://www.terratechnology.com/ Prices for these products range from about $5k-$20K. Good Luck! -Edward John Paul Martin wrote: > > Dear Sir, > > How do I go about obtaining the manufacturer and purchase price of a > PADS? My Email address is pinecone@............. > > John Paul Martin -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Karl Cunningham Subject: Flexures & Oilcans Date: Tue, 13 Jan 1998 14:40:02 -0800 Hi All -- In thinking about flexures, it seems there may be a natural tendency for microscopic oilcanning (non-linear spring characteristics of the flexure) as it changes from being bent one way to being bent the other way), due to irregularities in the thickness and flatness of the metal. Surely this has been thought of before -- does anyone know how this problem is dealt with in commercial instruments? Do they prevent the flexure from ever being flat by allowing it to only bend one way, or is some other technique used? wondering, Karl Cunningham La Mesa, CA. PSN station #40 karlc@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Francesco Subject: CIODAS08JR & EMON Date: Tue, 13 Jan 1998 23:54:18 +0100 Thank very much Bob, Ted and Jim. The I/O address it's ok and the board seems to function evenly. But I believe to have any other problem. If are not there events, must I see any trace in the screen or no? I see that the program runs, but I don't see any trace and no file is saved. Is that regular? These is the setting values: noise zones = 1% convert per sample = 25 buffers = 4000 Greetings FRANCESCO NUCERA OSIMO - Ancona - ITALY Lat. 43 29" E - Long. 13 29" E _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Roseberry Subject: GPS-based timekeeping for your PC Date: Tue, 13 Jan 1998 17:50:51 -0600 Hello group: A while back, this group developed a fairly long thread regarding GPS-based timekeeping. I happened onto the following source for these kinds of products and thought someone on the list may benefit from it. If you are interested in PGS stuff, see http://www.zeli.com for more details; their prices seem reasonable. Regards: Michael J. Roseberry Fort Worth, Texas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Charles R. Patton" Subject: Re: Radio Shack's Radio Controlled Clock Date: Tue, 13 Jan 1998 17:00:44 -0800 The Temic clock part is really a series of three parts of which seem to = be the same with only a difference of number of pins in the packaged = part. Of interest is that the app note shows two ways to use them with = one 60 KHz crystal or two crystals for the IF. In none of the radio = clocks I've seen, have they used the two crystal version--only one. = Cost, no doubt, but there is a significant improvement in performance = with two. As I've mentioned before, the Oregon Scientific "Time = Machine" and the Klockit analog movement unit all use the same RF = decoder it would appear. However, just before I found out about the = Temic chip, I had depotted a Klockit board, and the chip nomenclature = doesn't look like it fits the Temic brand. I know Integrated Display Co = in Hong Kong builds the Oregon Scientific line, and is big enough to = have a custom design done, and since Radio Shack imports a bunch, they = may be using the same chip. Be that as it may, Of the units I have = examined, the Oregon Scientific and the Klockit and information on one = other brand from another experimenter I've talked to, they all have the = 4 wire scheme just as Larry describes for the Radio Shack unit -- = power, ground, signal out, and inhibit. So if you want to start with = something cheaper, get the Klockit unit, it's only $30 and has the same = capability--you just have to slice and dice the circuit board a bit to = get those four connections -- but it really isn't too hard as the RF = section is confined to one end of the board. Be careful about the load = you place on the signal out line. The chip runs on only a few = microamps, so basically can't drive anything. I would suggest the use = of a CMOS buffer (inverter or such) between the data signal and your = computer input. I don't know the impedance of the line on Larry's = board, but running from 5V will help the driving capability somewhat. I've known about the Temic chips for some time and I'm in the process = of building up just boards to be interfaced to the computer. I have 4 = samples of the Temic SMT chips in my possession that I got last month, = and just got in the 60 KHz crystals last weekend (Digi-Key SE3320-ND = cylinder type watch crystals made by Epson for $1.35 each singles). = Rather than use ferrite rod antennas, I'm going to use a small loop, = which is more available and repeatable and should increase the = sensitivity to boot because the effective antenna height of the various = clocks is very small because they use such small antenna rods. I'll let you know how it works out when I finish. Charles R. Patton, Editor, Geo-Monitor patton@......... Sincerely yours, Charles R. Patton, Sr. Princ. Eng. Charles.R. Patton@....... fon: 714-932-7476 fax: 714-932-5995 Western Digital Corp. M/S 431 8105 Irvine Center Drive Irvine, CA 92618 _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jim Hannon Subject: Re: Radio Shack's Radio Controlled Clock Date: Tue, 13 Jan 1998 19:24:36 -0600 Charles R. Patton wrote: > > > > I've known about the Temic chips for some time and I'm in the process of building up just boards to be interfaced to the com puter. I have 4 samples of the Temic SMT chips in my possession that I got last month, and just got in the 60 KHz crystals las t weekend (Digi-Key SE3320-ND cylinder type watch crystals made by Epson for $1.35 each singles). Rather than use ferrite ro d antennas, I'm going to use a small loop, which is more available and repeatable and should increase the sensitivity to > I'll let you know how it works out when I finish. > Charles, I just found about the Temic chips today after talking to a person at Altera who is using the chip in a class to teach FPGA design. They have a FPGA design that converts the chip output into ASCII time info. He is supposed to be sending me the design and even a working clock for helping him find a source for the ferrite rods. (Amidon) It looks like we will have a nice WWVB time option for PSN soon. I ran out today and bought one of the Radio Shack clocks. :( -- Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N 91,39.26W WB0TXL _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: Flexures & Oilcans Date: Tue, 13 Jan 1998 06:36:20 -0800 Karl Are you refering to possible hysteresis of the metal? Barry Karl Cunningham wrote: > > Hi All -- > > In thinking about flexures, it seems there may be a natural tendency for > microscopic oilcanning (non-linear spring characteristics of the flexure) > as it changes from being bent one way to being bent the other way), due to > irregularities in the thickness and flatness of the metal. > > Surely this has been thought of before -- does anyone know how this problem > is dealt with in commercial instruments? Do they prevent the flexure from > ever being flat by allowing it to only bend one way, or is some other > technique used? _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: CIODAS08JR & EMON Date: Tue, 13 Jan 1998 06:40:48 -0800 Francesco Check which channel you are monitoring (F7 on my version) and make sure you have the correct entries for the other two of the three possible channels in the .OPT file. Barry Francesco wrote: > > Thank very much Bob, Ted and Jim. > > The I/O address it's ok and the board seems to function evenly. > But I believe to have any other problem. > If are not there events, must I see any trace in the screen or no? > I see that the program runs, but I don't see any trace and no file is > saved. Is that regular? > These is the setting values: > noise zones = 1% > convert per sample = 25 > buffers = 4000 _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: Radio Shack's Radio Controlled Clock Date: Tue, 13 Jan 1998 06:49:37 -0800 Charles I was interested in a low power accurate clock for my remote site , where I will be using a SBC. I would be interested in what you come up with. I was going to buy a Radio Shack clock but wasn't sure how to access the output to the display to input to my acquisition program. Barry Charles R. Patton wrote: > > > > I've known about the Temic chips for some time and I'm in the process of building up just boards to be interfaced to the com puter. I have 4 samples of the Temic SMT chips in my possession that I got last month, and just got in the 60 KHz crystals las t weekend (Digi-Key SE3320-ND cylinder type watch crystals made by Epson for $1.35 each singles). Rather than use ferrite ro d antennas, I'm going to use a small loop, which is more available and repeatable and should increase the sensitivity to > I'll let you know how it works out when I finish. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: Radio Shack's Radio Controlled Clock Date: Tue, 13 Jan 1998 18:27:54 -0800 At 10:43 AM 1/13/98 -0600, James M Hannon wrote: >Larry, >This is great! > >It is a little late maybe but the chip in the Radio Shack receiver part of >the clock is made by Temic Semiconductors part number U4223B Are you sure its the U4223b? This versions has an A/D convert built in to the chip and is meant for a direct connect to a micro processor. This would take more lines between the main unit and the receiver. >http://www.temic.de/semi/hn/broadcas/radiocon.htm is a link to the data >sheet on the chip. The chip costs about $2.50 each but it maybe hard to >get under the minimum order. Running the chip on 5 volts may be pushing >it. The data sheet gives 5.25 V as the absolute max . > >There are a number of time code transmitters in Europe that are more >powerfull than WWVB and radio controlled clocks and even wrist watches are >very popular there. Unfortunately they all use different formats and / or frequencies. Too bad they did'nt standardize them... -Larry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: flexure material Date: Tue, 13 Jan 1998 20:31:18 -0600 (CST) Karl et al. My experience with the flexures in commercial instruments has been that they are obtained from flat or rolled spring-steel or phosphor-bronze stock, and cut to length or size such that the sides that are cut are within the clamping mechanism: ie the portion that flexes is "original" rolled and hardened material. With regard to larger hinged "boom and mass" structured sensors, I am unaware of any major problem with latent curvature that would cause non-linearities. Actually, the spring constant of the flexures is quite small compared to the main suspension in a vertical, and weak compared with the gravitational restoring forces in a horizontal, where thin taught wires are preferred. If flexures are used in a horizontal, like the early sensors, they are installed so that any latent curvature will cancel in the crossed hinge arrangement . However, with the compact "geophone" type structures, made with usually etched circular springs, latent curvature is the name of the game. This is why simply inverting one of the 10 leaf springs in an L4-C can kill it; also why abuse can cause a partial inversion of a spring, changing the period to something very short. Which, of course, brings me to my favorite subject: in a fully fedback seismometer, the behavior of the hinges and springs doesn't show up in the transfer function, so it is a "don't care" item, generally speaking. By way of example, I just posted the data from the 10 Jan M=6.4 Guatemala quake, including a figure that compares the homemade STM-8 seis with the German-made STS-1s. I'm sure that there is a MAJOR difference between their hinges and my weatherstrip pieces, but with similar feedback, the data are basically identical in form, spectra, and amplitude (I've scalled them in microns/second), except for azimuthal variations of the stations wrt the earthquake source mechanism. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: meredith lamb Subject: STM-8 Bronze spring? Date: Tue, 13 Jan 1998 19:34:54 -0700 Sean-Thomas, Am curious about the "main" bronze weatherstrip spring under the boom. In past reviews of msgs, you state it is 12" X 3". What is the thickness of it, and where did you obtain it? Any possible other sources...i.e., machine shop supply? Shim stock in hobby shops? Could other materials, serve the same purpose with or without degradation of seismo output or metal fatique? I.e.,...flat sheet metal...galvanized sheet metal...etc.? I've only hit a local The Home Depot, but nothing approached that size. Perhaps anything that would provide the restoring force necessary.....and a To of 2-4 seconds.....may work? Thanks, Meredith Lamb _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: STM-8 steel spring! Date: Tue, 13 Jan 1998 21:05:39 -0600 (CST) Meredith, The main spring is spring steel from a drywall taping knife found in the PAINT department of Builders Square for about $8. It has a plastic handle, and is 0.018" thick, 3"wide, 12" long. There is nothing magic about the size; I just built a seismometer around it. One can buy the material in 70ft rolls from McMaster Supply. It needs to be hardened spring steel, though, since it is a spring. And my experience with this particular piece is that when it is bent to about a 5" opening, it exhibits some "zero length" behavior, where the force is somewhat constant over a short change in the length of the opening, allowing for a moderately long mechanical period without instability. The hinges, however, are phosphor-bronze weatherstrip, as are the flexures at the lower mount of the main leaf spring. It is 0.005" thick, and I used a width of 0.375 for the hinges and 0.75 for the spring flexure. I have been working on a detailed description of the mounting of the leaf spring, but I am not satisfied with the details of it yet. I did scan another photo to the web page that shows the hinges and some of the lower spring mounting detail. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: FM transmission Date: Tue, 13 Jan 1998 08:14:01 -0800 To all On a separate note; Do to my confusion about what was and wasn't allowed by the FCC with regards to transmitting data over the airwaves, does anyone know what the noise would be by sending analog signals(<20hz) over an FM transmitter? It is better practice to send "noise immune" digital data rather than analog data, but our signals are below the audible level. Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: RADIOTEL Subject: Re: EMON V7 available on PSN web site Date: Tue, 13 Jan 1998 21:49:09 EST TED BLANK: I just saw your posting about the availability of the new EMON package. I for one would like for you to know how much your efforts and contributions are appreciated. Thank you very very much. Jim Allen Cerritos, California _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jim Hannon Subject: Re: Radio Shack's Radio Controlled Clock Date: Tue, 13 Jan 1998 21:17:35 -0600 Larry Cochrane wrote: > > > Are you sure its the U4223b? This versions has an A/D convert built in to > the chip and is meant for a direct connect to a micro processor. This would > take more lines between the main unit and the receiver. > > -Larry > No I am not certain that is the exact chip. Maybe Charles Patton can clarify it for us. They could be using just one bit of the A/D output or just squaring up the AGC output. -- Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N 91,39.26W WB0TXL _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: meredith lamb Subject: STM-8 Steel Spring Date: Tue, 13 Jan 1998 21:28:19 -0700 Sean-Thomas, AAAHHHH the light goes on! Somehow, I transposed the dry wall knife as being at the back of the boom and the spring under the boom as being something else for a long month! I'll admit my gross error...and laughing at myself, really! I was mentally fixating on putty knifes! The spring is sprung.....thanks. Thanks for the other info, I'll be sure to take my micrometer along so I don't goof up as bad again. Thanks for all the work and effort you have put in over the long haul on this project, and although its been straining for people like me, I do appreciate all of this very, very much. Thanks, Meredith Lamb _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Seisguy Subject: Fwd: Italian Volcano Shows Lava Activity Date: Tue, 13 Jan 1998 23:24:30 EST This is being broadcast on the local L.A. news this evening also. Mike 
Italian Volcano Shows Lava Activity


.c The Associated
Press


 CATANIA, Sicily (AP) - The ground stayed quiet but experts remained alert
Tuesday for a possible eruption of Mount Etna, Europe's tallest volcano.

Two small lava streams continued to flow after several minor earthquakes
registered Friday evening and Saturday at the volcano in eastern Sicily.

Vulcanologists called the seismic activity serious, and said they were
watching for a potential eruption.

Etna's last major eruption came six years ago. No plans for evacuation have
been announced.

The volcano's slopes are home to several farm villages, and skiers enjoy the
mountain snow.

AP-NY-01-13-98 1711EST


 Copyright 1997 The Associated
Press.  The information  contained in the AP news report may not be published,
broadcast, rewritten or otherwise distributed without  prior written authority
of The Associated Press. 


 

To edit your profile, go to keyword NewsProfiles.
For all of today's news, go to keyword News.
From: "Al Allworth" Subject: Adjustment screws Date: Tue, 13 Jan 1998 23:03:53 -0800 Hi All, I have found a source of 1/4 X 80 pitch adjustment screws with brass nuts for $2.00 each at: http://www.lasersur.com/laser/accessories.htm With the 80 pitch thread it would probably not be necessary to use the differential thread construction. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Walt Williams" Subject: PSN - STM-8 steel spring & Zero Length Spring? Date: Tue, 13 Jan 1998 23:19:09 +0000 Hello Sean-Thomas Morrissey, Marquee: >>STM : Sean-Thomas Morrissey >>WW : Walt Williams ------- Forwarded Message Follows ------- Date: Tue, 13 Jan 1998 21:05:39 -0600 (CST) From: S-T Morrissey To: psn-l@............. Subject: STM-8 steel spring! Reply-to: PSN-L Mailing List >>STM The main spring is spring steel from a drywall taping knife..... <----- deletia -----> ......my experience with this particular piece is that when it is bent to about a 5" opening, it exhibits some "zero length" behavior, where the force is somewhat constant over a short change in the length of the opening, allowing for a moderately long mechanical period without instability. Regards, Sean-Thomas >>WW In literature of which some kind PSN-Ls have referred me, for the construction of gravimeter instruments, there is frequent reference to 'zero length springs'. I noticed you mention the drywall blade / spring metal can be made to exhibit 'zero-length' by flexing the metal. I am curious to know more detail about 'zero-length' characteristics, and why this is desirable. Could you explain how a 'zero-length' spring might behave? The whys would be interesting to know. Thank you. Walt Williams, 98.01.13 dfheli@.............. Canoga Park, (LA suburb), California USA _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Karl Cunningham Subject: Re: Flexures & Oilcans Date: Wed, 14 Jan 1998 00:05:31 -0800 Barry -- Yes, the effect of what I'm thinking of is hysteresis. I'm not sure just how to describe it except that it is similar to the action of the bottom of an oil can that "pops" in and out as you squeeze it. It's caused by an excess of metal in one area of the sheet, which means it must bulge either up or down. As the metal is flexed, this bulge can change from up to down and back, causing a non-linear displacement/force curve and hysteresis. -- Karl At 06:36 AM 1/13/98 -0800, you wrote: >Karl > Are you refering to possible hysteresis of the metal? > Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Francesco Subject: Re: CIODAS08JR & EMON Date: Wed, 14 Jan 1998 09:14:55 +0100 I checked the channel viewing: it's 0 and ok. The other possible channels are not installed and so the set in .opt file at line address 2^, 3^ ch. is 0. So, I'm using the 0 ch. and in pin connector i've choosed: pin n=B0 1 for input analog(positive) and pin 20 for ground. Is it right? If the connector from sensor is disabled from female board conn. the signal is a blank continuos line. When i connect the sensor that line disappear. Why?????? At last: in .opt file there is an option about ADC values. But the choose in the 3 option where is? Graciously Francesco At 06.40 13/01/98 -0800, you wrote: >Francesco > Check which channel you are monitoring (F7 on my version) and make >sure you have the correct entries for the other two of the three >possible channels in the .OPT file.=20 > Barry > >Francesco wrote: >>=20 >> Thank very much Bob, Ted and Jim. >>=20 >> The I/O address it's ok and the board seems to function evenly. >> But I believe to have any other problem. >> If are not there events, must I see any trace in the screen or no? >> I see that the program runs, but I don't see any trace and no file is >> saved. Is that regular? >> These is the setting values: >> noise zones =3D 1% >> convert per sample =3D 25 >> buffers =3D 4000 > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the=20 >message: leave PSN-L > > FRANCESCO NUCERA OSIMO - Ancona - ITALY Lat. 43 29" E - Long. 13 29" E _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Karl Cunningham Subject: Re: Speaker coil-based seismos Date: Wed, 14 Jan 1998 08:32:17 -0800 I have found used speakers at swap meets that have screwed-together magnet assemblies. Usually a disc-shaped ceramic magnet (with a hole in the center) sandwiched between two metal plates with screws between the metal plates. Some even have threaded holes in which to insert jack screws to controllably force the pieces apart. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: bob ogburn Subject: Re: Adjustment screws Date: Wed, 14 Jan 1998 09:29:53 -0800 the correct URL is: http://www.lasersur.com/laseraccessories.htm Al Allworth wrote: > > Hi All, > > I have found a source of 1/4 X 80 pitch adjustment screws with brass nuts > for $2.00 each at: > http://www.lasersur.com/laser/accessories.htm > > With the 80 pitch thread it would probably not be necessary to use the > differential thread construction. > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: meredith lamb Subject: A Lunchpail Amateur Seismologists Best Story Date: Wed, 14 Jan 1998 12:30:27 -0700 Hi group, Back in the mid 1960's, I first got interested in amateur seismology mainly due to the series of Denver, Colo. area earthquakes induced by the Army's Rocky Mountain Arsenals fluid injections by a well on the northeast outskirts of Denver. For me these were as close as you can get the majority being Mag 2 or so. These quakes seemed to be fairly often, and over time I tried to develop a sensitivity for them regardless of personal activity. For me in those days, amateur equipment was essentially not available due to price and wallet scantiness for other than daily living costs. My best shot at the time was the Heathkit Company with its discrete parts chart recorder...not to buy...but to build from their schematic. The servo motor I bought from them, the rest of the stuff was salvage here & there. I didn't fare too well, as the circuit often broke down. Chart paper was out of the question; too costly, so I ended up with using a homebrew drum made out of a plexiglass 8" tube, mechanics, and mounting the servo motor over the drum, and yes, the old screw rod translation drive. Yes, breakdowns all the time. My biggest financial purchase at the time, was a set of Sprengnether LP seismometers, so...no problem with that aspect. $240.00,...seems small now, but for the time that was about 2 weeks of take home earnings. Anyway...this was the first crude seismograph I had, and the excitement was very high. I had it setup in the basement. Had a problem with the low gain, but who cares for the minor stuff. Believe me...its hard to ignore the first masterpiece, and I would often sit in an old wooden rocker with footrests and wait for something to show. One night (I forget the year), soon thereafter, I was sitting and watching and all stretched out on the rocker....and fell asleep. >From a very slow awakening state, I realized I was slowly being rocked in the chair by a period of perhaps 15 seconds. At first, I thought someone was gently rocking me, and slowly turning...there was no one there! A quick glance at the drum drum showed long period surface waves being recorded! The quake date I don't remember, but I think it was off the coast of Portugal in the Atlantic, perhaps 7.8 ~, in the latter 60's. This quake made seiches in lakes in northern europe, and also made me a living mass and sensor in a way also. So.......enough of mine......whats your best story? Thanks, Meredith Lamb _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "James M Hannon" Subject: Re: FM transmission Date: Wed, 14 Jan 1998 13:43:27 -0600 Barry, Directly FM modulating a radio carrier with the low frequency seismic signals is not a good idea. There are all sorts of problems with the receiver and transmitter design that would cause this to be very unsatisfactory. Most of these problems are solved by modulating the radio carrier with an audio frequency signal that is itself fm modulated by the seismic signal. I am not sure what you are referring to about what is or is not allowed by the FCC but: If you are not already a licensed Amateur radio operator you might want to consider getting at least the no code amateur radio operators license. This license will allow you to operate all sorts of radio transmitters and transmit digital data or analog seismic signals. You do have to pass a written test but it is not too hard after reading through the license book a couple of times. http://www.arrl.org is a good place to start for information. Also http://www.tapr.org is group involved in digital radio communications. Jim Hannon WB0TXL gbl@....... on 01/13/98 10:14:01 AM Please respond to psn-l@............. To: psn-l@............. cc: (bcc: James M Hannon/CedarRapids/Collins/Rockwell) Subject: FM transmission To all On a separate note; Do to my confusion about what was and wasn't allowed by the FCC with regards to transmitting data over the airwaves, does anyone know what the noise would be by sending analog signals(<20hz) over an FM transmitter? It is better practice to send "noise immune" digital data rather than analog data, but our signals are below the audible level. Barry _____________________________________________________________________ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Dewayne and Linda Hill Subject: Re: A Lunchpail Amateur Seismologists Best Story Date: Wed, 14 Jan 1998 13:01:08 -0700 Hi Mereidth, Good to get your note last night and your natural earth resonant rocker story was quit good also. Well I just got back to the office from hardware store (another $20 on the project.) I pickup everything I need to rebuild the boom with the exception of the coil and magnet. I sent Larry an E-Mail about ordering his coil/magnet. After re-reading my description about the Lehman I can see how you misunderstood part of the write up. I boom is not at 37degs., the supenition wire is at 37degs. Hope you haven't trying to picture a 37deg boom all night. I bought 5lb. of lead. It looks like steel wool. How is the best way to melt down? Does the lead pour have to be made in one pour or can I do it in several small pours? Well I have to get back to work. Dewayne _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Charles R. Patton" Subject: Re: Radio Controlled Clock Date: Wed, 14 Jan 1998 12:46:52 -0800 I just revisited the spec sheets on the Temic site which you can reach = with: http://www.temic.de/cgi/prod_head.tcl?headline=3DRadio-Controlled+Clock+R= eceivers+ICs&parent=3Dabroadc&ueber=3DCommunication+Ics The four parts available from Temic are: Part Function Key Features Package T4225B Receiver for 40 to 80 kHz Extreme low power consumption Die U4223B Receiver for 40 to 80 kHz 4-bit ADC output SSO20 U4224B Receiver for 40 to 80 kHz Extreme low power consumption SO16L U4226B Receiver for 40 to 80 kHz Extreme low power consumption SSO20 Since I have no intention of doing high production, chip-on-board, the = T4225B is dismissed. The U4223B can do a 4 bit digitization of the AGC and the incoming = signal (these are all TRF receivers with rectification type detectors). = By doing signal processing you can improve the detection capability by = 10 dB (says the spec sheet). But this would require oversampling, at = least a 6 wire interface, and a bunch of processor code. Not sure that = the effort is warranted. So that brings us to the last pair of numbers, = the U4224B and U4226B. The only thing I've been able to figure out = that's different is that the package is a 16 pin vs. 20 pin SOIC. = Anyway these have the 0/1 output controlled by a comparator inside the = chip monitoring the AGC vs. the current signal strength (modulation). They basically are very simple to use. They require 3 non-electrolytic = caps, 1 resistor, 1 tuned antenna, and 1 or 2 60.00KHz crystals. They = use a maximum of 25 uA at 5 V while operating, but the output is = guaranteed for 3 to 4 uA only, which is why I commented about buffering = the output for most uses. I want to expand on my comment about the antenna. One simplistic way of = viewing a ferrite antenna is that its length is its important dimension = and if you have a loop whose side is that length, they become = comparable. Since ferrite rods used in the current radio controlled = clocks on the market are only about 3" or 4" long, then a loop antenna = the size of your hand, can easily best them. And that way you don't get = involved in the temperature curves of the ferrite, or procurement = difficulties. (This is another way of looking at the effective = permeability curves of ferrite rods based on their length/diameter = ratios.) Hope this helps. Charles R. Patton, Editor, Geo-Monitor patton@......... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Norman Davis WB6SHI Subject: Re: A Lunchpail Amateur Seismologists Best Story Date: Wed, 14 Jan 1998 13:17:10 >I bought 5lb. of lead. It looks like steel wool. How is the best >way to melt down? >Does the lead pour have to be made in one pour or can I do it in >several small >pours? I bought lead shot. Got an old can. Put it on a coalman stove and poured a little at a time untill it was all melted then let it cool. Getting the can off was fun. Norman Davis WB6SHI Email normd@............. Shingle Springs, Ca, USA it ain't local... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "James M Hannon" Subject: Re: Radio Controlled Clock Date: Wed, 14 Jan 1998 15:23:17 -0600 Charles, Thanks for the info! My only concern with the air loop antenna is the pickup of stray E field noise and how to use up a box of 12" ferrite rods. :) Jim Hannon _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: meredith lamb Subject: Re: A Lunchpail Amateur Seismologists Best Story Date: Wed, 14 Jan 1998 14:24:34 -0700 Dewayne and Linda Hill wrote: > Hi Mereidth, > > Good to get your note last night and your natural earth resonant > rocker story was > quit good also. > > Well I just got back to the office from hardware store (another > $20 on the project.) > I pickup everything I need to rebuild the boom with the exception > of the coil and > magnet. I sent Larry an E-Mail about ordering his coil/magnet. > A: If your IBM mainframe computer magnet is truly a rare earth type of not.....keep it by all means....the larger the magnet, the more the flux....the more the emf....the more the signal...the less the amplification you may need. Rare earth magnets can range from 12K to 15K gauss. Alnico magnets...wide range, but they do a very good job also....uhh....perhaps 750 gauss. Larrys will be very effective I'am sure. Some of my best overall magnet and coil combos still (regardless of super rare earths) are the alnico type with relay coil or other shapes of coils (square). I don't know the gap of the IBM magnet, but consider using it with your coil....or even series of coils.....and another set of coils for eddy current damping if there is enough room. Check out the local surplus scene...over time....theres a world of coils out there! > After re-reading my description about the Lehman I can see how > you misunderstood > part of the write up. I boom is not at 37degs., the supenition > wire is at 37degs. > Hope you haven't trying to picture a 37deg boom all night. > A: Hey....first mistake I made in a whole 12 hours! ...Yes I thought you said you were going to put the boom at a 37 degree angle....not the suspension wire. > I bought 5lb. of lead. It looks like steel wool. How is the best > way to melt down? > Does the lead pour have to be made in one pour or can I do it in > several small > pours? > A: If it was me....and my past lead pouring experiences...I wouldn't even bother to melt it. Drill it if its one piece. You might consider putting it in a plastic container and also drilling a hole big enough for the boom,..with 2 side holes tapped for a screw to lock to the boom. Melted lead is very dangerious and time consuming to mess with. Drill a hole on top for your suspension wire attachment. If the container is too big for the lead, you might consider dropping in a bunch of those pesky pennys laying around....if it doesn't work out, you can always retrieve your investment......ahem! Watch out for the lead poisoning aspect...use gloves, and if you drill it as it is, paint over it afterward, well. Personally, I would get a bunch of pennys instead of lead for the mass...you don't lose or spend money, but you use it....as is. Well I have to get back to work. > Dewayne > > A: Although you are probably inpatient, try to make every pieceas well as you can....it may save repair time, down the seismic road. Above all, research everything possible and don't be afraid to change things around, if something may work better. Your's is a Lehman type....the main thing is too have fun with it.... Later...down the road...consider S-T's seismo...for its features. Regards, Meredith Lamb.....the unskilled lunchpail seismometrist _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Charles R. Patton" Subject: Re: Radio Controlled Clock Date: Wed, 14 Jan 1998 14:52:48 -0800 Jim, If you really have "...a box of 12" ferrite rods", we could design it to use them, if you want to make them available to the group under some arrangement. At 12", a rod would be significantly smaller than a 12" square coil of wire. Charles Patton _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Karl Cunningham Subject: Re: A Lunchpail Amateur Seismologists Best Story Date: Wed, 14 Jan 1998 15:14:56 -0800 Meredith -- Very interesting story. I've been very curious if anyone has been able to "feel" a teleseismic event, and you did! Another curiosity this brings to mind is to make a "perpetual motion" machine -- a high-Q mechanism resonant at 6-seconds to pick up the background noise. The idea is to have this thing sitting there constantly moving. Perhaps a rocker with a strategically placed mass could be made into such a thing. I guess my best story is about going to Landers a few days after the big event and seeing boulders the size of a two-car garage that had tumbled down a hill, and seeing the almost 8-meter horizontal and 2.6-meter vertical offsets along the fault. There were ruptures everywhere on little fault strands going this way and that. I was standing about 5 meters away from the fault near the area of greatest offset when a M5+ aftershock occurred. I didn't feel anything, but heard a VERY low frequency rumble -- perhaps 15Hz and very loud. It sounded as though the nearby mountains were talking. I detected no movement of the fault and saw no dust, though. Karl Cunningham La Mesa, CA. PSN station #40 karlc@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Charles R. Patton" Subject: Re: speaker force feedback devices Date: Wed, 14 Jan 1998 15:32:12 -0800 One quick point I'd like to make. Today's typical voice coil actuator in a hard disk drive memory has force constants in the 10 oz/amp with 10 to 20 ohm coils. This should be more than sufficient for the force balance equation until you get accelerations (from seismic activity) in the fraction of a G range which would be local strong motion, and the seismometer might have other problems at that point. The gaps on both sides of the coil are in the neighborhood of 0.010". The important thing is that if the coil is aligned flat in the plane of movement of the boom, you have almost an inch of movement available. The force won't be as flat as originally designed since the coil is designed to pivot around the bearing cartridge about 1 " away, but for small movements that would not enter the equation since a force balance design essentially holds the boom in a constant position, the assumption should be correct. I have seen crashed, removed from equipment, etc. drives for only a few dollars at surplus stores. At this point I hesitate to volunteer, but send me an email direct to my work address above if you're willing to pay for the postage/shipping on a magnet/voice coil assembly, and I'll see if the company is willing to donate junk drives from FA to the cause. If there's enough interest, I'll follow it up. Be aware of bureacratic red tape, as it will take awhile to get permission, if at all. In particular, I need Sean to verify my comment that 10 oz/amp is sufficient. Also one other comment for analysis, in high performance actuators, the L/R of the coil causes a pole in the response compromising the high frequency response, so all the actuator drivers use transconductance (current) amplifiers (as Karl was alluding to). This essentially removes the R from the equation. It only fails when the compliance range of the amplifier runs out such as when high acceleration is commanded and there is not enough head-room (the VCC supply) to achieve the current commanded. Sean's circuit is a voltage drive, so the L/R becomes a significant item. I don't want to criticize though, because it takes at least one more op-amp, and in our circuits, we use still another opamp and a sense resistor in series with the coil to measure the current (in this way we solve the stability problem of the negative impedance converter mentioned by Karl). But these circuits would add thermal drifts to the feedback, and so might not be worth the tradeoffs. But for the die-hard experimenter who wants to try and get a high resistance coil geophone unit working with force feedback, this might offer the path. Charles R. Patton _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jim Hannon Subject: Re: speaker force feedback devices Date: Wed, 14 Jan 1998 18:55:40 -0600 Charles R. Patton wrote: > > One quick point I'd like to make. Today's typical voice coil actuator in > a hard disk drive memory has force constants in the 10 oz/amp with 10 to > 20 ohm coils. This should be more than sufficient for the force > balance equation until you get accelerations (from seismic activity) in > the fraction of a G range which would be local strong motion, and the > seismometer might have other problems at that point. The gaps on both > sides of the coil are in the neighborhood of 0.010". The important > thing is that if the coil is aligned flat in the plane of movement of > the boom, you have almost an inch of movement available. The force > won't be as flat as originally designed since the coil is designed to > pivot around the bearing cartridge about 1 " away, but for small > movements that would not enter the equation since a force balance design > essentially holds the boom in a constant position, the assumption should > be correct. > > I have seen crashed, removed from equipment, etc. drives for only a few > dollars at surplus stores. At this point I hesitate to volunteer, but > send me an email direct to my work address above if you're willing to > pay for the postage/shipping on a magnet/voice coil assembly, and I'll > see if the company is willing to donate junk drives from FA to the > cause. If there's enough interest, I'll follow it up. Be aware of > bureacratic red tape, as it will take awhile to get permission, if at > all. > > In particular, I need Sean to verify my comment that 10 oz/amp is > sufficient. > > Charles R. Patton > > I did a quick calculation and if I did my metric conversions right Sean's speaker has a force constant of 45.5 OZ/AMP. This is not too far from the 10 oz/amp of the hard drive actuator. I don't quite have all the equations pluged into mathcad or I would give the numbers a try. I want to build a instrument with a slightly shorter boom so the hd actuators may work quite well for me. All Electronics http://wwwallcorp.com has some of the magnet assemblies in their catalog for $2.50 each. No coils though. -- Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N 91,39.26W WB0TXL _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jim Hannon Subject: Re: Radio Controlled Clock Date: Wed, 14 Jan 1998 18:59:07 -0600 Charles R. Patton wrote: > > Jim, > If you really have "...a box of 12" ferrite rods", we could design it to > use them, if you want to make them available to the group under some > arrangement. At 12", a rod would be significantly smaller than a 12" > square coil of wire. > Charles Patton > Well maybe "a box" was an exageration. I went out to the shop and counted them. I have 9 not counting the one I already built into a WWVB antenna. I am willing to send them to whoever wants one for shipping ect. -- Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N 91,39.26W WB0TXL _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Charles R. Patton" Subject: Re: Radio Controlled Clock Date: Wed, 14 Jan 1998 17:29:39 -0800 Jim, I'd love to take you up on the "deal" how much do they weigh, and I'll send postage. Also I would need an address to send to! The longest rods I have are about 4" long so I was planning on a 9" or so square coil, so a 12" ferrite would be better. Thanks, Charles R. Patton work: patton@.......... 714-932-7476 home: patton@......... 909-698-9657 21490 Camino Arriba Murrieta, CA 92562 _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: coils,FM,lead,etc Date: Wed, 14 Jan 1998 19:38:40 -0600 (CST) Charles,Darrel,Dewayne, Karl, Meredith, and co: Answering various topics: Regarding the disk drive actuator: if I calculated correctly, 10 oz/ amp is 283.75gm/A or 0.28375gm/ma * 9.806 (g) = 2.78 N/A (Newtons/Ampere), which is rather weak (~21%) compared with the 10" speaker (~13N/A). This design is probably a major compromise for the long stroke length and the clearance needed. I must again emphasize that the VBB feedback is NOT a VOLTAGE circuit, but a summation of characteristic CURRENTS through the force coil producing accelerations of the mass based on the information from the displacement transducer. It is fundamentally different from the traditional force=balance feedback. Regarding the inductance of the coil, one can include its' effect on the transfer function in the third and fourth order terms, but, as you observe, it will affect only the high frequency response. Regarding the BSSA article by Roberts: my copy here says Vol 79, No 4, pp 1607-1617, October 1989. Regarding FM telemetry: we use a VCO (voltage controlled oscillator) for every analog channel to create FM audio carriers on the standard IRIG (Inter Range Inter Government: set up for early rocket data telemetry) frequencies (680, 1020, 1360, 1700, 2040, 2380, 2720, 3060, etc, hz). They are multiplexed together, so we can send 8 to 10 channels over a narrowband (5khz wide) FM link and/or a phone line. We use a discriminator at the receiver/data collection end to recover the analog data; each discriminator has an input filter that "listens" to its particular carrier among the multiplexed audio, and then a PLL (phase locked loop) follows the frequency change of the carrier, and the lock voltage is the original analog data. Regarding melting lead: I agree with the cautions. Just pack the wool into a handy container, like a pill jar or whatever. Mass is mass. But prefer lead over brass, because the atmospheric buoyancy noise is inversely proportional to the density of the mass. Regarding feeling earthquakes: in the Aleutians, we could sometimes "predict" an event if we sensed the P waves. Since the events were all south of the islands, the time between P and S was usually 10 to 15 seconds. So if I felt a P wave while at dinner with the Navy personnel, I would say "I think we are about to have an earthquake", which is just about enough time for the S-wave to arrive and rattle everything. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: JHammes@......................... Subject: Re[2]: Radio Controlled Clock Date: Wed, 14 Jan 1998 17:51:44 -0800 Jim, I would like a couple, just let me know your address and the check is on it's way, thanks. Jerry Hammes Palo Alto ______________________________ Reply Separator _________________________________ Subject: Re: Radio Controlled Clock Author: PSN-L Mailing List at CCSMTP Date: 1/14/98 6:59 PM Charles R. Patton wrote: > > Jim, > If you really have "...a box of 12" ferrite rods", we could design it to > use them, if you want to make them available to the group under some > arrangement. At 12", a rod would be significantly smaller than a 12" > square coil of wire. > Charles Patton > Well maybe "a box" was an exageration. I went out to the shop and counted them. I have 9 not counting the one I already built into a WWVB antenna. I am willing to send them to whoever wants one for shipping ect. -- Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N 91,39.26W WB0TXL _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: FM transmission Date: Wed, 14 Jan 1998 07:36:01 -0800 James Thanks for your assistance. I think you are correct about the license. I hope to do this in the very near future. I need to find out about tests-study mat'l etc. Thanks for the links. Barry James M Hannon wrote: > > Barry, > Directly FM modulating a radio carrier with the low frequency seismic > signals is not a good idea. There are all sorts of problems with the > receiver and transmitter design that would cause this to be very > unsatisfactory. Most of these problems are solved by modulating the radio > carrier with an audio frequency signal that is itself fm modulated by the > seismic signal. > > I am not sure what you are referring to about what is or is not allowed by > the FCC but: If you are not already a licensed Amateur radio operator you > might want to consider getting at least the no code amateur radio operators > license. This license will allow you to operate all sorts of radio > transmitters and transmit digital data or analog seismic signals. You do > have to pass a written test but it is not too hard after reading through > the license book a couple of times. http://www.arrl.org is a good place to > start for information. Also http://www.tapr.org is group involved in > digital radio communications. > > Jim Hannon > WB0TXL > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: Radio Controlled Clock Date: Wed, 14 Jan 1998 09:28:00 -0800 Charles I'm not to familiar with radio waves/antennas but I just read an article from Joe Carr in Nuts & Volts about antennas( specifically WWVB. Have you seen the article? In one design he uses a loop of ribbon cable. Do you think one of these antennas would work with the chip? Barry Charles R. Patton wrote: > > I just revisited the spec sheets on the Temic site which you can reach with: > http://www.temic.de/cgi/prod_head.tcl?headline=Radio-Controlled+Clock+Receivers+ICs&parent=abroadc&ueber=Communication+Ics > > The four parts available from Temic are: > Part Function Key Features Package > T4225B Receiver for 40 to 80 kHz Extreme low power consumption Die > U4223B Receiver for 40 to 80 kHz 4-bit ADC output SSO20 > U4224B Receiver for 40 to 80 kHz Extreme low power consumption SO16L > U4226B Receiver for 40 to 80 kHz Extreme low power consumption SSO20 > > Since I have no intention of doing high production, chip-on-board, the T4225B is dismissed. > > > They basically are very simple to use. They require 3 non-electrolytic caps, 1 resistor, 1 tuned antenna, and 1 or 2 60.00KH z crystals. They use a maximum of 25 uA at 5 V while operating, but the output is guaranteed for 3 to 4 uA only, which is why I commented about buffering the output for most uses. > > I want to expand on my comment about the antenna. One simplistic way of viewing a ferrite antenna is that its length is its important dimension and if you have a loop whose side is that length, they become comparable. Since ferrite rods used in the c urrent radio controlled clocks on the market are only about 3" or 4" long, then a loop antenna the size of your hand, can easil y best them. And that way you don't get involved in the temperature curves of the ferrite, or procurement difficulties. > > Hope this helps. > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: speaker force feedback devices Date: Wed, 14 Jan 1998 09:36:44 -0800 Jim I took apart a harddrive about a month ago. What concerned me was the potential friction in the pivot. Do you think it may be to high? Barry Jim Hannon wrote: > > > > I did a quick calculation and if I did my metric conversions right > Sean's speaker has a force constant of 45.5 OZ/AMP. This is not too far > from the 10 oz/amp of the hard drive actuator. I don't quite have all > the equations pluged into mathcad or I would give the numbers a try. I > want to build a instrument with a slightly shorter boom so the hd > actuators may work quite well for me. All Electronics > http://wwwallcorp.com has some of the magnet assemblies in their catalog > for $2.50 each. No coils though. > -- _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: Speaker coil-based seismos Date: Wed, 14 Jan 1998 09:56:25 -0800 Roger I centered the coil in a brass tube that was about 1/2" bigger in diameter than the coil. I then used 6 brass screws at 120 deg. apart oriented radially( 3 @ two locations along the length). I was not to difficult to center the coil. Sean Thomas's suggestion about using 50 mph tape to remove particles worked for me. I agree though one will need a sealed enclosure to keep future particles out. The epoxy is strong. A year ago I tried to separate the plates and broke the magnet. I think temperature will affect the magnetism so one may have to take care with temp. I am not sure what temp is ok. Barry Roger Baker wrote: > > Friends, > Upon investigating some of the idiosyncrasies of speaker coils as > sources of force for force feedback,(and this actuator looks like it might > be the best way to go for a whole bunch of related force feedback-related > instrument designs yet to come), it appears that one of the trickiest parts > is getting the coil properly recentered whenever the coil is removed and > remounted. An intact paper speaker cone absorbs seismic energy. The > cylindrical coil is precision made and needs to be carefully protected > against deformation from its normal circular shape. > > The speaker manufacturers are clearly skilled at making sure the axis of > travel of the cylindrical coil coincides exactly with the annular magnet > gap, since the clearance is only a few thousandths of an inch. Therefore > remounting the coil on a beam is likely to cause the moving coil to rub > against the gap somewhere, in my experience. This problem may be worse with > smaller speakers. > > Also, the bare gap strongly attracts stray particles of iron which are hard > to see, hard to get out, and probably cause killer friction if they remain. > > Speaker magnets are usually made of an top iron plate with a hole and > epoxied to a black ceramic magnet donut. Then an iron backplate with a > stout cylindrical iron pole protruding from the center is epoxied to the > back of the donut so the pole sticks up through the hole, creating a narrow > annular magnetic gap. It is useful to know how to enlarge this gap > slightly, with a slight loss in electromechanical efficiency. This does not > eliminate the necessity of being able to make fine adjustments to make sure > that the coil is exactly centered with respect to the magnet gap. > > If we disassemble the magnet, we can enlarge the hole in the top plate > slightly with a dowel or drill bit wrapped with carbide paper, file down > the center pole a little too, and then glue everything back together. > > This may be done by softening the epoxy by slowly heating the magnet in a > frying pan over a low flame. Wedge a sharp point in the gap of the hot > magnet, (probably about the boiling point of water or a little hotter) and > one of the iron plates should pop loose. Then we can let everything cool, > clean the surfaces, enlarge the gap slightly, and epoxy everything back in > place. Because the gap spacing is unstable due to magnetic force, we need > to carefully shim the gap to keep it even in width, perhaps with a ring of > sheet metal or paper wound around the center pole or some such spacer while > the new epoxy sets up. > > --Yours, Roger > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: speaker force feedback devices Date: Wed, 14 Jan 1998 10:18:07 -0800 Jim Another source for magnets might be Dowling Miner Magnetics Corp. in Sonoma Calif. I got one of their catalogues a while back. They have several different geometries and materials but they ain't cheap. Barry Jim Hannon wrote: > .... All Electronics > http://wwwallcorp.com has some of the magnet assemblies in their catalog > for $2.50 each. No coils though. > -- _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: zero length spring Date: Wed, 14 Jan 1998 23:31:15 -0600 (CST) Walt, Regarding "zero length" beahvior of a spring. For an ordinary spring, as it it stretched, the change in length is proportional to the force applied. If you attach a linear dial an put it in a box and step on it, it will tell you how well you prospered fron the holiday feasting. ie Hooks law: F = k *(l - lo), where k is the spring constant (force/unit length), l is the length with the force F applied, and lo is the initial length. When such a spring is used in a vertical seismometer, this means that the restoring force changes as the boom moves, making the sensor non-linear. This was solved in the 30s by the LaCoste suspension that devised a spring such that at a specific length the change in force with change in length became zero. That is, if lo = 0, so F = k*l, then F is constant. So any minute acceleration will move the mass in a linear fashion. So when such a spring is made, namely by twisting the wire (or quartz fiber in gravimeters) as the coil is wound, the spring ends up forcibly closed: it takes an initial force to open it. I won't go into the math to determine the constants, but at some opened length, lo becomes 0. With the leaf spring I use, this occurs at about a 5" opening, and is evident when the spring is installed and the opening adjusted. At one point, the boom will not stay balanced, but floats either up or down with instability (aka an infinite period). So I increase the opening slightly, and the period becomes stable. A stable period is essential for a well defined transfer function. Regards, Sean-Thomas !p _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: Re: Speaker coil-based seismos Date: Wed, 14 Jan 1998 23:39:26 -0600 (CST) Barry and Roger, The speaker I use has the magnet assembly both glued and riveted together. As tempting it is to increase the clearance for the coil, it will definitely reduce the force constant. I generally have little trouble aligning the coil, but I have had problems with stray dog hairs falling in. If I were to try to improve the speaker application, I would try to wind a single layer coil in place of the two layer coil, on an inside former with more clearance. As it is, it works fine. Also, significantly heating the magnet, or even removing the steel pole plates, will probably weaken it. I suspect that the magnet is charged (magnetized) after it is assembled, as we do when making magnets for large seismometers. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Roger Baker Subject: Re: Speaker coil-based seismos Date: Thu, 15 Jan 1998 03:24:00 -0600 At 11:39 PM 1/14/98 -0600, you wrote: >Barry and Roger, >The speaker I use has the magnet assembly both glued and riveted >together. As tempting it is to increase the clearance for the coil, >it will definitely reduce the force constant. I generally have >little trouble aligning the coil, but I have had problems with >stray dog hairs falling in. If I were to try to improve the >speaker application, I would try to wind a single layer coil in >place of the two layer coil, on an inside former with more >clearance. As it is, it works fine. > >Also, significantly heating the magnet, or even removing the >steel pole plates, will probably weaken it. I suspect that >the magnet is charged (magnetized) after it is assembled, as >we do when making magnets for large seismometers. > >Regards, >Sean-Thomas Dear Sean-Thomas, et al, Actually, the reason I posted the piece on diassembling speaker magnets by heating them is that I am currently experimenting with a small Sanyo speaker that only weighs 45 grams, has a coil resistance of 32 ohms. The coil gap was only 20 thousandths of an inch total, most of which was occupied with the coil. Its a tight fit. I'm experiimenting on an unusually small scale primarily to learn about the physics of different mass suspensions and circuit behavior without the inconvenience of building a large instrument, and because such a scale is more compatable for possible eventual adoption with my existing temperature feedback control and hermetic enclosure abilities (for the latter I have the cut off top of a gallon jug as a bell jar and a glass plate for a base. This arrangement can hold a slight vacuum for at least a week I have found.) I am currently using my own miniature leaf spring arrangement to support about a five gram mass and the feedback coil. (My other leading contender for this purpose is to use a magnetic spring and knife edge pivot combination). Anyhow, I had great difficulty with my coil clearance adjustments with the current arrangement until I widened the annular gap to perhaps 40 thousandths. Loudspeakers have just the right design properties to move masses of various sizes fast. Bottom line: I suspect small force feedback instruments based on small speakers may have their own role to play in amateur seismology. Thats the kind of stuff I love to find out for myself. At any rate, the magnet surgery was successful and widened the gap so the coil no longer binds with the suspension I am using and the magnet does not seem to have suffered much in observable properties. I vaguely recall that the Curie point of ceramic magnets might be about 300 C, and if one always stays below the Curie point for the particular ceramic magnet composition in question, the strength of the magnet should not suffer much, I think. Some of the larger speakers I saw at Radio Shack seem to have an almost identical construction and I see no reason why it should not be possible to widen the gaps of many larger speaker magnets as needed, and if needed (once you peel off the iron frame, the magnet looks kind of like an iron hockey puck with a black rim, and the latter is what you heat). As usual, I am using a light beam as my displacement sensor, and as things now stand there is plenty of feedback power to keep the mass oscillating at a frequency that depends greatly on the exact characteristics of the feedback circuit. I'm using a small twelve volt lead acid battery for power. I like to design with 324 quad op amps, and they put out 20-40 millamps of current (depending on whether you're sourcing or sinking your current). If needed, you can parallel several of them configured as voltage followers through 10 ohm load sharing resistors to drive the coil directly without any power transistor stage. If the feedback force exerted on the spring and mass is weak, the oscillation frequency is slow (the natural period of the mass and coil and spring assembly without the coil connected up to restore the position of the mass is even lower of course). As the gain is turned up, the speaker magnet acts like a stiffer and stiffer spring that tries to restore the position of the mass and the oscillation period decreases accordingly. Despite widening the gap, which obviously must weaken the magnetic force somewhat, there's plenty of force left for my purposes. Of course the ultimate goal is to rapidly damp the oscillations that result from a sudden displacement and end up with the fastest most stable and linear response. As with much of life, there are many practical ways to get fair results and a few ways to get optimum results. Suffice to say I'm having fun playing with various components on a plug-in circuit board and learning how the electronics interacts with the mechanics. --Yours, Roger _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: RLLaney Subject: Re: A Lunchpail Amateur Seismologists Best Story Date: Thu, 15 Jan 1998 10:35:29 EST Saw the comments on melting down lead wool, etc. Sounds like the hard way. At plumbing shop I was able to get 5 pound hunks of lead about 4 inches in diameter and about 2 inches thick. Simply drilled a hole in the center and slipped onto the Lehman boom. They also make nice sized weights for making sure the instruments and coils have good contact with the floor. I would assume that lead in this form would be common elsewhere. For what it's worth. Bob Laney Herndon, VA _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: watson@................ (Charles Watson) Subject: Northern CA/NV Quake Date: Thu, 15 Jan 1998 07:41:20 -0700 We just had a small temblor up here along the Northern California/Nevada border region. Measured ~M3.8 and was centered 10 miles N of Truckee near Sierraville. Widely felt, from Truckee and Tahoe Donner to Quincy. -- ---/---- Charles P. Watson, Consulting Geologist Advanced Geologic Exploration Seismo-Watch / Earthquake Information Services Voice: 702-852-0992 / Fax: 702-852-3226 Office Location: 39.43N 119.71W mailto:watson@................ http://www.seismo-watch.com _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Larry P. Thomas WA0GWA" Subject: VBB feedback Current vs Voltage Date: Thu, 15 Jan 1998 10:05:10 -0600 I've been following this SIG for some time but been too busy to really contribute much. There seems to be a difficulty understanding that the currents sum in the force coil on the VBB system. I thought I'd offer an alternate explanation. Due to the very very low impedance of the coil (mostly resitive athe frequencies of interest) when compared to the impedance of any other component connected to the ungrounded side of the coil we can really consider it to be a virtual ground, much like the input to a high gain operational amplifier. In other words, changes in current from one leg feeding the coil have almost no effect on any other leg feeding the coil because no significant voltage change is caused by this current. The coil is simply a non-ideal (but almost) current summing junction. Just as in a good operational amplifer with high gain where any output possible from the opamp can be obtained with virtually zero input voltage making the input a current summing node, the coil can produce the required force with virtually no applied voltage. Force is a function of the current in coil and not the volatage across it. I hope to make this VBB design my first actual sensor. I really enjoy this SIG and want to thank those that contribute Later Larry Thomas >I must again emphasize that the VBB feedback is NOT a VOLTAGE >circuit, but a summation of characteristic CURRENTS through >the force coil producing accelerations of the mass based on the >information from the displacement transducer. It is fundamentally >different from the traditional force=balance feedback. >Regarding the inductance of the coil, one can include its' effect >on the transfer function in the third and fourth order terms, but, >as you observe, it will affect only the high frequency response. ----------------------------------------------------------------------- Larry P. Thomas wa0gwa voice : 1 913 888-0282 Krell Technologies fax : 1 913 782-9359 8960 Bond pager : 1 816 989-HELP Overland Park, KS www : http://www.krell.com 66214-1764 e-mail : mailto://lpthomas@................ ----------------------------------------------------------------------- _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: John Fell Subject: Re: Purchasing Seismograph -Reply Date: Thu, 15 Jan 1998 16:20:29 +0000 Thanks for the advice, second hand but no less helpfull. John _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: meredith lamb Subject: STM-8 spring opening determines construction? Date: Thu, 15 Jan 1998 10:13:32 -0700 S-T Morrissey wrote: > Walt, > > Regarding "zero length" beahvior of a spring. > > For an ordinary spring, as it it stretched, the change in length > is proportional to the force applied. If you attach a linear dial > an put it in a box and step on it, it will tell you how well you > prospered fron the holiday feasting. ie Hooks law: F = k *(l - lo), > where k is the spring constant (force/unit length), l is the length > with the force F applied, and lo is the initial length. > > When such a spring is used in a vertical seismometer, this means > that the restoring force changes as the boom moves, making the > sensor non-linear. This was solved in the 30s by the LaCoste > suspension that devised a spring such that at a specific length > the change in force with change in length became zero. That is, > if lo = 0, so F = k*l, then F is constant. So any minute > acceleration will move the mass in a linear fashion. > > So when such a spring is made, namely by twisting the wire > (or quartz fiber in gravimeters) as the coil is wound, the spring > ends up forcibly closed: it takes an initial force to open it. > I won't go into the math to determine the constants, but at some > opened length, lo becomes 0. > > With the leaf spring I use, this occurs at about a 5" opening, and > is evident when the spring is installed and the opening adjusted. > At one point, the boom will not stay balanced, but floats either > up or down with instability (aka an infinite period). So I increase > the opening slightly, and the period becomes stable. A stable > period is essential for a well defined transfer function. > > Regards, > Sean-Thomas > Sean-Thomas, If I interpret the last paragraph right, then all reproseismo's should be constructed pretty much based on the ~ 5" opening of the spring. I.e......boom height and everything else must follow a accomodating distance based on the preferential transfer function of the spring. Any other type of construction must somehow find adjustable ways of achieveing this rough 5" opening. (?) Regards, Meredith Lamb _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Charles R. Patton" Subject: Potpourri: Re: VBB fdbk, lead weights, VLF loop ants Date: Thu, 15 Jan 1998 10:41:17 -0800 VBB feedback: Larry P. Thomas explained my point very well. The coil in Sean's circuit is being used as a virtual summing node. So as long as its resistance is low in relation to the other components' resistance and reactance, the feedback coil's resistance doesn't matter much and it is current driven. But as that resistance rises, the virtual ground statement no longer holds and the other term in the equation reflects this change. That can be fixed by using opamps which can provide the virtual ground and force the current independent of the coil's resistance. As a practical question -- how far does the boom physically swing up and down in the VBB design while force feedback is in operation? By design of the feedback sensor, total travel can only be about +- 1 mm. If so, then the long throw of a voice coil in a speaker really doesn't matter. For instance the use of the hard drive actuator coil with approximately 5:1 less force/amp says you could just rescale the output components C, Rp and Ri. The problem then starts to be the large values of C (approx. 120 uF) and low value of Ri (approx. 21 K) so that you might have to add one high current output opamp to be the virtual summer and capable of driving the weaker actuator coil structure. Barry Lotz wrote: >What concerned me was the potential friction in the pivot. I think there is a bit of a misunderstanding here. I agree the pivot bearing in a drive would not be at all suitable for the pivot on the seismometer. Sean's crossed hinge is much better. What I was thinking (you know the old saying, "Do what I think, not what I say!") is to cut the voice coil off of the drive actuator and glue it to the end of the boom and use it instead of the speaker force feedback coil system. The magnet structure of the drive would be mounted in a vertical sense so the coil could go up and down with the boom (for a vertical seismometer) or horizontal for a Lehman style. The force would be more non-linear over the stroke of an 1" or so, because the curvature of the magnet structure is designed for the radius to the pivot bearing in a drive (approx. 1" instead of the boom length of about 24"). But in a stroke of 1 mm or so, this should be insignificant. Roger mentioned that the speaker coil has a gap of 0.020" or so, This is about the same for the actuator. However several things are in your favor: 1) the geometry of the boom to gap using the actuator magnet does not imply any change in the gap, since the gap is parallel to the swing and 2) if you want more gap, the actuator magnet structure is very easy to shim open more as it is just held together magnetically (at least it is in our product.) If you do that, I would strongly suggest using magnetic materials for the shimming, to minimize the field strength loss. 3) Shimming an actuator has much less effect than it does to a speaker because the gap the coil is in is already much larger than in the speaker, so the proportional change is much less. So in conclusion, it should be a much more forgiving structure to use in a force feedback seismometer using beams. LEAD WEIGHTS: 5 pound (?) lead bricks are available in home building supply stores as the weights for "Bull" floats. (A "Bull" float is the large flat bladed tool used to finish off the surface of wet cement floors after they have been poured.) This was the cheapest lead I could find easily when I needed some for ladder counterweight I poured. LOOP ANT: Barry Lotz wrote: "...In one design he uses a loop of ribbon cable. Do you think one of these > antennas would work with the chip? The Temic spec sheet says the antenna must have a minimum of 1.5 uV and a minimum Q of 30. I haven't read the Nuts and Volts article, but using ribbon cable for a loop strikes me as a bunch of hassle to solder the wires together. Various construction techniques I've seen over the years have used pipe through which they pulled a bunch of wire and then soldered them into one continuous loop. Instead my thought on this process would be to take PVC pipe and make into a square of the size you want using standard ell joint couplers (or if you want a round shape, use sweep ells, but you'll be limited to certain sizes). After the glue sets up, grind the outside perimeter of the pipe all the way through to expose the inside all the way around. Wind your coil in this "hula hoop". Once you have the number of turns you want, obtain a roll of aluminum foil duct tape (couple of $ for a small roll 3" wide.) Run this over the whole length, but stopping with a gap so you don't form a shorted turn. Now you have an electrostatic shield you can ground to your feed cable shield and the perimeter gap has been sealed with a weatherproof, ozone proof covering of aluminum. Haven't done it yet, but this is the method I was going to use for the Temic chip when I breadboard it. so wait a while if you want, and I'll let you know how it works out! Charles R. Patton patton@......... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: Rockland filter Date: Thu, 15 Jan 1998 14:46:41 -0500 Dewayne, I have no manual for the Rockland filter. I posted all the info that I= have. I'm aware of the places which sell manuals but haven't tried them.= = If you get one, let me know. Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: Re: A Lunchpail Amateur Seismologists Best Story Date: Thu, 15 Jan 1998 14:46:43 -0500 Norman Davis, Lead can be cast in a wood mold. I use a router bit in a drill press t= o cut a cavity in any wood, even pine. You get some smoke when the lead is= poured in but the cavity can be used many times. In fact, the first casting may have some bubbles from the water in the wood but this gets better as the wood chars. For my Lehman weight, I made 4 slabs about 3/= 8" thick and then soldered them together using sticks of lead and a Bernzomatic torch. Sticks of lead can be made by placing an aluminum angle standing on its= point and casting lead in the groove. It is best to do a lead casting in one pour. Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: Re: FM transmission Date: Thu, 15 Jan 1998 14:46:45 -0500 Jim Hannon, Amateur radio transmissions require that the station ID be given at lea= st every 10 mins. This might be a major complication in transmitting continuous seismic data. Bob Barns KB2IKC _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: Radio Shack's Radio Controlled Clock Date: Thu, 15 Jan 1998 14:46:48 -0500 Larry, = Fascinating stuff about the Radio Shack clock! Thanks. Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Subject: Re: FM transmission Date: Thu, 15 Jan 1998 14:31:02 -0600 (CST) On Thu, 15 Jan 1998, Robert L Barns wrote: > Jim Hannon, > Amateur radio transmissions require that the station ID be given at least > every 10 mins. This might be a major complication in transmitting > continuous seismic data. > Bob Barns > Bob, I am aware of the ID requirements and I guess I did not think it would be a big problem. If you are using the fm audio subcariers you could include a subcarrier that was modulated with the ID continuously. If you are sending digital data you could send and ID in between data packets every so often. Jim Hannon WB0TXL _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Norman Davis WB6SHI Subject: Re: FM transmission Date: Thu, 15 Jan 1998 12:35:37 -0800 At 02:46 PM 1/15/98 -0500, you wrote: >Jim Hannon, > Amateur radio transmissions require that the station ID be given at least >every 10 mins. This might be a major complication in transmitting >continuous seismic data. >Bob Barns >KB2IKC > Also there is the thing about broadcasting. Don't know how the FCC would like that. There has been some talk about encodeing quake data into the APRS system Amature Possiton Reporting System. It would plot the quake on a map. I am not a hacker when it comes to that stuff but you would need a latlong embedded into a packet beacon string and then everyone could see it on the map. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Charles R. Patton" Subject: Re: zero length spring Date: Thu, 15 Jan 1998 13:47:22 -0800 Check out the URL: http://www.lacosteromberg.com/detail.html#physics The site is LaCoste-Romberg Co. and the particular URL is pointing at a section of their manual which describes the theory and construction of the zero-length spring and LaCost suspension in a gravity meter. Back up a bit, and you can get a full education on gravity meters they manufacture. I'm amazed. This is the first site I have come across that puts their equipment manuals on line. Charles R. Patton patton@......... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: VBB CURRENTS Date: Thu, 15 Jan 1998 16:37:51 -0600 (CST) Charles, I must again emphasize that in the triple feedback VBB configuration the CURRENTS that flow through the force coil are controlled by the actual reactances of the three feedback elements, whose input is either the displacement voltage or the integral of it. These ARE NOT filters; they actually convert the mass displacement voltage into the characteristic current that shapes the acceleration response of their respective portion of the response curve. There can be NO amplifier or other device between the summing junction of Rp, Cp, and RI and the force coil, since this would prevent these currents from flowing. There is in fact NO VOLTAGE to amplify. The transfer function actually describes an assembly of equations of accelerations that are produced by each characterisstic feedback path. This acceleration response is converted to the flat velocity response by multiplying through by omega. Another important point to notice is that the VBB output voltage is obtained from the displacement transducer output, which BECOMES the VBB output WHEN and ONLY when the triple feedback is functioning. THis is a unique feature of this VBB circuit. Turn off the feedback, as when the boom needs to be recentered, and the output is that of an undamped mechanical sensor swinging freely at To. Re-connect the feedback, and the seismometer output immediately recovers as a VBB sensor with a period of Tn . Also notice that the output still contains the DC displacement information, which is reduced (by the current feedback parameters) by about a factor of ten. ie if the VBB output indicates 5 volts, and r=500mv/micron, the mass offset is 10 microns with the feedback on, but will shift to 100 microns if I disconnect the feedback. Also, if 5 volts is the limit of the displacement amplifier output, it is also the limit of the feedback DC operating range, in this case, +- 100 microns. (NOT to be confused with the dynamic range of the velocity output) Other force balance feedback configuations obtain a voltage function of acceleration across the force coil. This is not the case here. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Karl Cunningham Subject: Re: A Lunchpail Amateur Seismologists Best Story Date: Thu, 15 Jan 1998 15:01:45 -0800 Thought I'd add my $.02 about melting lead: I bought one-pound ingots and melted them with a home-shop type (Berzomatic) propane torch. I made a mold out of brass sheet, soldered together. I held the ingot over the mold with a pair of pliers and melted the lead a drop at a time, playing the torch on the ingot. Each drop would solidify in the mold after a couple of seconds. This avoided the danger of pouring a quantity of molten lead, and the mold never even got hot enough to melt the solder holding it together. Karl Cunningham La Mesa, CA. PSN station #40 karlc@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: spring opening Date: Thu, 15 Jan 1998 17:03:24 -0600 (CST) Merdith, THat is the case (5.5") for that particular spring. I have been wanting to try something about half the size, with an 8" boom, if I can get the coil to move freely in the magnet. BTW: the coil clearance of the 10" dual-coil RS speaker is about 0.005 all the way around. I use a thin strip of 0.005" plastic to check the gap to make sure it is symetrical when I install the magnet. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: W6JRF Subject: Re: A Lunchpail Amateur Seismologists Best Story Date: Thu, 15 Jan 1998 18:15:44 EST Two more cents for the melting lead story. Be absolutely certain the mold that is to receive the molten lead is dry. If you pour the lead into a confined mold and there is any moisture in it, you will find that you made a miniature volcano powered by steam! I know, I've been there and done that. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jim Hannon Subject: Re: FM transmission Date: Thu, 15 Jan 1998 18:27:46 -0600 Norman Davis WB6SHI wrote: > > > Also there is the thing about broadcasting. Don't know how the FCC would > like that. > There has been some talk about encodeing quake data into the APRS system > Amature Possiton Reporting System. It would plot the quake on a map. I am > not a hacker when it comes to that stuff but you would need a latlong > embedded into a packet beacon string and then everyone could see it on the > map. > > _ -- Norman, Just to be sure I went and back and read the FCC rules again. 1: Telemetry is specifically permitted by the rules. 2: Broadcasting is transmitting to nonamateurs or transmitting without a specific recipient. Since in this case one would be transmitting to yourself a licensed amateur it would not be broadcasting. There are some rules about control of an unattened transmitter but there are ways of meeting those requirements. Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N 91,39.26W WB0TXL _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: spring opening Date: Thu, 15 Jan 1998 07:02:39 -0800 All I had success with this option also. I used a short piece of large diameter shrink tubing that I cut longitudinally. After I secured the coil I removed the plastic. Barry S-T Morrissey wrote: > > BTW: the coil clearance of the 10" dual-coil RS speaker is about > 0.005 all the way around. I use a thin strip of 0.005" plastic > to check the gap to make sure it is symetrical when I install > the magnet. > > Regards, > Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Ted Blank Subject: Re: CIODAS08JR & EMON Date: Thu, 15 Jan 1998 17:56:47 -0800 (PST) Hi Francesco, If I understand you correctly, you are not seeing any data trace (line)=20 on the screen, right? When this happens to me, it is usually a mistake in the values for=20 ADCValueAtMinVolts, ADCValueAtMaxVolts or ADCValueAtZeroVolts. =20 Here is what to do. Start EMON and then press F2. This will start=20 showing the actual sample value (a number) in the upper left corner of=20 the screen. If this value stays near zero, then your A/D board range=20 should be Max=3D2047, Zero=3D0 and Min=3D-2048. If the value you see sta= ys=20 near 2048, then your A/D board range should be Max=3D4095, Zero=3D2048 an= d=20 Min=3D0. =20 Please try the F2 and tell us what numbers you see. Also, have someone=20 jump up and down near the sensor and tell us what the highest and lowest=20 number you see. Regards, Ted >=20 > I checked the channel viewing: it's 0 and ok. > The other possible channels are not installed and so the set in .opt fi= le > at line address 2^, 3^ ch. is 0. > So, I'm using the 0 ch. and in pin connector i've choosed: pin n=B0 1 f= or > input analog(positive) and pin 20 for ground. Is it right? > If the connector from sensor is disabled from female board conn. the si= gnal > is a blank continuos line. When i connect the sensor that line disappea= r. > Why?????? > At last: in .opt file there is an option about ADC values. But the choo= se > in the 3 option where is? > Graciously > Francesco >=20 >=20 > At 06.40 13/01/98 -0800, you wrote: > >Francesco > > Check which channel you are monitoring (F7 on my version) and make > >sure you have the correct entries for the other two of the three > >possible channels in the .OPT file.=20 > > Barry > > > >Francesco wrote: > >>=20 > >> Thank very much Bob, Ted and Jim. > >>=20 > >> The I/O address it's ok and the board seems to function evenly. > >> But I believe to have any other problem. > >> If are not there events, must I see any trace in the screen or no? > >> I see that the program runs, but I don't see any trace and no file i= s > >> saved. Is that regular? > >> These is the setting values: > >> noise zones =3D 1% > >> convert per sample =3D 25 > >> buffers =3D 4000 > > > >_____________________________________________________________________ > > > >Public Seismic Network Mailing List (PSN-L) > > > >To leave this list email listserver@............. with the body of the= =20 > >message: leave PSN-L > > > > > FRANCESCO NUCERA > OSIMO - Ancona - > ITALY >=20 > Lat. 43 29" E - Long. 13 29" E >=20 >=20 > _____________________________________________________________________ >=20 > Public Seismic Network Mailing List (PSN-L) >=20 > To leave this list email listserver@............. with the body of the=20 > message: leave PSN-L >=20 _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: FM transmission Date: Thu, 15 Jan 1998 07:07:53 -0800 Jim My thought was to acquire a number of quakes by a proper trigger routine and then transmit the data when the remote memory filled up (flash card preferably) or when the data was requested. This way there shouldn't be continuous transmitting. Barry >Jim Hannon wrote: > Just to be sure I went and back and read the FCC rules again. 1: > Telemetry is specifically permitted by the rules. 2: Broadcasting is > transmitting to nonamateurs or transmitting without a specific > recipient. Since in this case one would be transmitting to yourself a > licensed amateur it would not be broadcasting. There are some rules > about control of an unattened transmitter but there are ways of meeting > those requirements. > > Jim Hannon > http://soli.inav.net/~jmhannon/ > 42,11.90N 91,39.26W > WB0TXL _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Bob Thomasson <102073.3346@..............> Subject: Northern CA/NV Quake Date: Thu, 15 Jan 1998 23:10:36 -0500 <>= Charles, I felt it right here too - about a half mile N of the NDF fire station on= Mt Rose Hwy. A single abrupt jolt that also made the house creak, at 0703 on my watc= h. = Bob Thomasson _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Lengthing Period Date: Thu, 15 Jan 1998 09:46:29 -0800 Sean Thomas et al I have a vertical pendulum that I am configuring as a VBB horizontal sensor. It has an approx. length of 8" with a period of 0.9-1.0 sec. I am trying to increase the period without increasing the mass. I have put additional weight at the pivot point at the same elevation as the pivot thus increasing the moment of inertia but I believe not increasing the mass in the horizontal plane, increasing the period to 1.35 sec. Do you think there is a way to increase the period by the use of flat springs, geometry etc rather than weight? I would like to keep the sensor under 12" tall. Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: meredith lamb Subject: Seismic Surplus Scene And The Holy Grail Date: Thu, 15 Jan 1998 22:40:56 -0700 It used to be...(oh NO; not another story), that back in the 1960's it was a feast of sorts or mostly famine for surplus stuff. Good stuff like working chart recorders where a premium thing and you NEVER saw them in surplus stores. Trinkets like round plexiglass tubes of maybe 8" diameter (drums) were around here, as were alot of nice rolls of various sizes of enameled copper wire, as were lead ingot piles, precision rods of steel and all manner of juicy thick aluminum plates. Nowadays this stuff doesn't seem as readily available...or so it seems. Military surplus stores sometimes carried objects of interest. Electronic surplus stores were the prime bug eyed places to hit every so often...you never know...was the primary high anticipation motive, to visit them frequently. Hitting the stores on weekends was akin to the excitement of a new discovery. Sometimes you find "gold" and you could salt it away for that big combination that yields something of value...but mostly it was; and still is....a piece meal quest. Dunno...but...I think that if you're limited to just surplus stores, you may be depriving yourself of what I seem to think maybe a worthwhile source...the local metal junkyard (metal & salvage boutique). One old source (in the 1960's, not now) in the Denver area frequently bought all manner of metal and scrapped and sorted it out in piles. (I suppose most of them do this) Anyway...I LOVED this place...piles of electronic cards, occasional chart recorders of military voltages (24vac 3 phase), unopened government boxes with mystical writing on them which tempted me to inspect the innards every time. Once they had huge racks of strip chart recorders, but alas...they wanted a ransom for each ($100.00), well...they instead later scrapped them apart. To help you salivate more, they once had about six barrels of the 52 gallon variety, filled to the brim with big solid one piece alnico magnets, which they would sell for $6.00 each. Temping, but I already had magnets. WHEEEE EUREKA! Uhhh....maybe limited piece meal....but when you're starving! Anyway that was 30 odd years ago. So, check out your local or not so local boutique, which some of you do anyway. Nowadays the electronic surplus scene presents a continual reminder of the 60's it seems..same old, same old. Chart recorders?...yea the old clunkers are around...now...like Texas Instrument Rectiwriters or Esterline-Angus pen motor jobs. These are good for magnets...but the imprecision is HORRIBLE, and even if you can approach making them work, and the paper can be found, and the ink, and the replacement parts, or jerry rigged repairs and etc., etc. UGGHHHHH! This is alright for me to say, as I'am a senior drummer. Ahem! This is not to say you can't find stuff that works, you can, you just have to be in the right place at the right time. Overall though, (for me), the electronics surplus stores still need to have their periodic inspection....and it is still a long time between finding something REALLY worthwhile. If you're a true blue lunchbucket seismometrist you do this stuff....the thin wallet and the code of the west thing. Coyote in the desert. YEA.....I know...the computer age is here. Actually its looking better all the time...especially since this computer and its infamous GPF's seem to have disappeared over the last week or so. This gives me pause to consider that aspect more and more. The initial outlay is relatively large but...it may work consistently, which my chart recorders don't do (drummers delight). Well....I'll have to have a spam sandwich and think alittle more about that. The future perpetuation of the seismic scene addiction is probably here already. Too me...this STM-8 stuff is coming on strong...and the juicy piece meal aspect involved that does not depend on discovering the gold in the surplus mines. Somehow I'am feeling more rejuvinated, and can even manage to get my socks on in the morning...eventually...after turning on the home computer...however coffee is 2nd in line. Sooooo....what am I telling you this for... I guess because the past is still the present....the holy grail thing....otherwise you wouldn't read this at all. (Is there a hidden message here....or something??... :>) Thanks, Meredith Lamb.....the lunchbucket seismometrist unDictionary meaning of: seimometrist: One who continually seeks the perfect combination of cheap reliable seismograph, but who may show frequent quirks from the as yet unsucessful quest for the holy grail. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: meredith lamb Subject: The Colorado Springs Meteorite Date: Fri, 16 Jan 1998 07:41:38 -0700 Todays Denver Post newspaper had an update on the meteor of last Sunday. Actually it states that the likely impact area (if any), may be closer to the town of Elbert, Colorado which is maybe 25 miles north east of Colorado Springs. Triangulation efforts continue from witnesses. Any effort to find fragments may not be fruitful till spring. A guesstimate of total fragment weight may range upward to 60 pounds. The meteor came in from the southwest, brilliant white to blue, multiple booms heard, breakup in flight into 2 or 3 pieces and then it winked out. Earlier witnesses mentioned house vibrations before the booms were heard. Thanks, Meredith Lamb _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: John Hernlund Subject: Re: The Colorado Springs Meteorite Date: Fri, 16 Jan 1998 13:56:11 -0700 (MST) On Fri, 16 Jan 1998, meredith lamb wrote: > Todays Denver Post newspaper had an update on the meteor > of last Sunday. Actually it states that the likely impact area > (if any), may be closer to the town of Elbert, Colorado which > is maybe 25 miles north east of Colorado Springs. Triangulation > efforts continue from witnesses. Any effort to find fragments > may not be fruitful till spring. A guesstimate of total fragment > weight may range upward to 60 pounds. > The meteor came in from the southwest, brilliant white to > blue, multiple booms heard, breakup in flight into 2 or 3 pieces > and then it winked out. Earlier witnesses mentioned house > vibrations before the booms were heard. That is funny, because I saw a spectacular meteorite falling Sunday night in the NE sky here is Mesa AZ. Is it possible that this could be the same one??? ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Francesco Subject: Re: CIODAS08JR & EMON Date: Fri, 16 Jan 1998 13:30:16 +0100 I I had set the option about vertical compression display at 40, and now I see trace. The number of sample is near 3000. Now the problem is to save the file. In the last hours there were some events in my zone (3.7 Mb). I saw the traces during the event, but the files are not saved. Why? My actual configuration is: NoiseRangeToIgnore =3D 1.5 (ok for my area) =20 SampleCountToSaveFile =3D 2 =20 SamplesPerDataPoint =3D 25 =20 What I can do? I'm waiting your precious help Regards. Francesco At 17.56 15/01/98 -0800, you wrote: >Hi Francesco, > >If I understand you correctly, you are not seeing any data trace (line)=20 >on the screen, right? > >When this happens to me, it is usually a mistake in the values for=20 >ADCValueAtMinVolts, ADCValueAtMaxVolts or ADCValueAtZeroVolts. =20 > >Here is what to do. Start EMON and then press F2. This will start=20 >showing the actual sample value (a number) in the upper left corner of=20 >the screen. If this value stays near zero, then your A/D board range=20 >should be Max=3D2047, Zero=3D0 and Min=3D-2048. If the value you see stays= =20 >near 2048, then your A/D board range should be Max=3D4095, Zero=3D2048 and= =20 >Min=3D0. =20 > >Please try the F2 and tell us what numbers you see. Also, have someone=20 >jump up and down near the sensor and tell us what the highest and lowest=20 >number you see. > >Regards, Ted > >>=20 >> I checked the channel viewing: it's 0 and ok. >> The other possible channels are not installed and so the set in .opt file >> at line address 2^, 3^ ch. is 0. >> So, I'm using the 0 ch. and in pin connector i've choosed: pin n=B0 1 for >> input analog(positive) and pin 20 for ground. Is it right? >> If the connector from sensor is disabled from female board conn. the= signal >> is a blank continuos line. When i connect the sensor that line disappear. >> Why?????? >> At last: in .opt file there is an option about ADC values. But the choose >> in the 3 option where is? >> Graciously >> Francesco >>=20 >>=20 >> At 06.40 13/01/98 -0800, you wrote: >> >Francesco >> > Check which channel you are monitoring (F7 on my version) and make >> >sure you have the correct entries for the other two of the three >> >possible channels in the .OPT file.=20 >> > Barry >> > >> >Francesco wrote: >> >>=20 >> >> Thank very much Bob, Ted and Jim. >> >>=20 >> >> The I/O address it's ok and the board seems to function evenly. >> >> But I believe to have any other problem. >> >> If are not there events, must I see any trace in the screen or no? >> >> I see that the program runs, but I don't see any trace and no file is >> >> saved. Is that regular? >> >> These is the setting values: >> >> noise zones =3D 1% >> >> convert per sample =3D 25 >> >> buffers =3D 4000 >> > >> >_____________________________________________________________________ >> > >> >Public Seismic Network Mailing List (PSN-L) >> > >> >To leave this list email listserver@............. with the body of the= =20 >> >message: leave PSN-L >> > >> > >> FRANCESCO NUCERA >> OSIMO - Ancona - >> ITALY >>=20 >> Lat. 43 29" E - Long. 13 29" E >>=20 >>=20 >> _____________________________________________________________________ >>=20 >> Public Seismic Network Mailing List (PSN-L) >>=20 >> To leave this list email listserver@............. with the body of the=20 >> message: leave PSN-L >>=20 > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the=20 >message: leave PSN-L > > Francesco Nucera Osimo - Italy Lat.43.29N Long.13.29E _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: watson@................ (Charles Watson) Subject: Re: Northern CA/NV Quake Date: Fri, 16 Jan 1998 15:17:00 -0700 If you go outside and wave, I could probably see you from my office window. :> I'm at the top of the Virginia Foothills development near the red roof barn house, Rancho Verde Drive. Although I was probably sitting here at the ol' Mac, I missed the quake. UNR said it was felt in Carson City; I doubt it, that's pretty darn far away for a M3.8 (USGS) or M3.5 (UNR) -- ---/---- Charles P. Watson, Consulting Geologist Advanced Geologic Exploration Seismo-Watch / Earthquake Information Services Voice: 702-852-0992 / Fax: 702-852-3226 Office Location: 39.43N 119.71W mailto:watson@................ http://www.seismo-watch.com _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Erich F. Kern" Subject: e-mail address Date: Fri, 16 Jan 1998 15:23:13 -0800 This is primarily for Meridith Lamb; I just had 2 e-mails returned as address unknown. The address I used for Meridith is: psnseismograph52@.......... If you have a correction for this would you please send it. Thanks Erich Kern *************************************************************** Please visit our web site at: http://www.dconn.com/FatQuartersSoftware Thank you *************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: pendulum periods Date: Fri, 16 Jan 1998 20:40:09 -0600 (CST) Barry, re simple aand inverted pendulums: Inverted pendulums were very popolar in the days of optical magnification, and, yes, they have considerable instability problems. In fact, some ingenious oil-filled dash-pots were used in an attempt to couple shorter period velicity or displacement output to the mirror systems while attenuating the tilt noise. The chief drawback of an inverted pendulum is that all the parameters are locked up in the mechanics; they cannot be readily adjusted, and many things/parts are thermometers, like the spring stiffness, etc. Aside from this, a reasonable mechanical system can be used in the VBB configuration. But since the 50's, horizontals have used the "Press-Ewing" or garden-gate configuration, either with the vertical-post-wire- to-mass-with-reversed-taught-wire hinge like the Columbia- Sprengnether LP, or the vertical crossed-flexure hinge, which is suitable for smaller masses, like the commercial VBB sensors. I used it on the prototype horizontal that is shown on a photo on the web page. (the entire hinge-post-flexure assembly is epoxied together; if you want more photos, I will scan them; ps.:I am interested in feedback on what you want to see vs size, etc. I just found my old close-up lens for my SLR camera). Regarding your question of yesterday about simple pendulums: Simple means that the support has minimal mass, like a string. The period is independent of the mass for small angles. This is why kids and their parents swing at about the same period on the swing set in the park. The period is: Tn = 2*pi*sqrt(L/g), L in meters, g=9.806. So a 1-second pendulum is 0.248 meters long, or 9.78 inches, which is a very handy length for pendulum escapement wall clocks. If we want a real long period, like 20 seconds, the length is about 100 meters. 30 seconds takes 225 meters, or the atrium of a 80 story building (makes a nice Focault (spelling?) pendulum.) But impractical for a seismometer. But a real physical pendulum has distributed mass, and Tn= 2*pi*sqrt(k/(M*g*r)), where k is the moment of inertia, r is the distance from the pivot to the Cm (center of mass), and M is the mass. So now the L of a simple pendulum is equal to k/(m*r), which is called the "reduced" pendulum length. What you were observing as you increased the mass was that the moment of inertia k was increasing, lengthening the period. But the period can never be longer than that of a simple pendulum of the same length. So the determining factors are L and g. So if you can reduce the proportion of g acting on the mass, the period lengthens by the square root of the change. So if we make a "rigid" hinge, and turn the suspension sideways to become a boom, we can get 1% of g at a small angle, and our 9.78 inch pendulum now has a period of 10 seconds rather than 1. As the angle approaches true horizontal, the percentage of g goes to zero, and neglecting the hinges, the period becomes infinite. I hope this answers your questions, regards Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: meredith lamb Subject: Computers....UUGGHHHHH! Test...msg Date: Fri, 16 Jan 1998 21:16:25 -0700 Erich Kern, Apparently you are right, my US West mail server was down and not accepting anything from anywhere. From AOL to US West, it doesn't seem to make any difference for me, problems of one nature or the other. I expected more from US West...dreaming I guess....they are all imperfect. If I were fishing for a positive note this time, it wasn't my computer at fault. In the humor aspect, just last night I mentioned that I hadn't had problems for about 2 weeks........MURPHY Bingo! Question to PSN members, anybody have a national server, that has like a perfect record? Pse let me know...thanks. Erich, ok on your similar surplus adventures in California. Them were the good old days....in a way. Actually part of the Seismic Scene article was pointing away from the past that we have known, and re-directing the reality of it all more toward the present days goodies. The prospect of the present looks alot more inviting than stuff of the past, mainly because of the availability of common components. Back to the past: Yes I have a drum recorder, but it isn't in use....no amplifiers. I speculate on using it for a strong motion general type machine sometime. Missing parts too. Currently I use an Easterline-Angus Speed Servo II strip chart recorder circa maybe the mid 70's. One of my better cheapo finds....$35.00 in a surplus store. It looked like it had little use, too clean, no ink stains. Turned out that whoever had it before had tried to load a chart roll that was too wide and stripped one of the rubber drive belts. Converted to a long length "drum" recorder, simply by removing the shredded take up belt. The ink reservoir was also damaged...removed and put in my own pen holder and use Pilot razor point pens, which are good for 4-5 days of use. Installed a bigger zero pot and connected a mechanical gizmo mechanism for the 24 hour span. 20 year old thing, and capacitors do their last gasp thing occasionally. Fast for a chart recorder in response. Nice for viewing whats going on now, but the reliability thing is a problem that doesn't go away. 3 days to convert. Chart recorder or drum, kind of the same thing, but certain chart recorders allow for a long conveyor belt like "drum". Well....here I am carrying on too far again... This msg is really a "test" msg. If I were just to say test on a msg, nothing is conveyed if its successful. Thanks for the 3 inquirys today. Regards, Meredith Lamb _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: meredith lamb Subject: Re:Photo Feedback on STM-8 AND prototype horizontal Date: Fri, 16 Jan 1998 22:09:24 -0700 S-T Morrissey wrote: (parts of previous msg deleted) > But since the 50's, horizontals have used the "Press-Ewing" or > garden-gate configuration, either with the vertical-post-wire- > to-mass-with-reversed-taught-wire hinge like the Columbia- > Sprengnether LP, or the vertical crossed-flexure hinge, which > is suitable for smaller masses, like the commercial VBB sensors. > I used it on the prototype horizontal that is shown on a photo > on the web page. (the entire hinge-post-flexure assembly is > epoxied together; if you want more photos, I will scan them; > ps.:I am interested in feedback on what you want to see vs size, > etc. I just found my old close-up lens for my SLR camera). > Sean-Thomas > > Sean, I would be interested in an additional photo on the web that reveals more details of your STM-8, which close-ups the spring retention mechanisms. Both the bottom base and the upper on the boom. I have stared at the horizontal for several days and am also very interested in the hinge mechanism from what every angles or closeups are possible. The broad view is good but its the closeups that click on understanding. The hinge-boom attachment from the above is also a subject of interest. Also any details I can't see that are of a major difference from the vertical, mechanically. Am pushing my luck....as all this takes gobs of time for you I'am sure, but...more details overall of the horizontal will be very much sought after by myself and probably a mob of the rest of us on the PSN and web. Guess I'am really offering encouragement to publish and appreciation. Thanks, Meredith Lamb _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: EAservoII Date: Fri, 16 Jan 1998 23:17:28 -0600 (CST) Meredith, That Esterline Angus Servo II recorder has been the workhorse of my monitor recording drums at SLU for the past 28 years, and they are still going. For one triple drum recorder (we have four) , three EA units were reassembled with the electronics installed in a rack drawer and the linear pen motors mounted to a pivot bar (to lift the pens to change the paper) above a modified 3-channel photographic drum. The drums rotate every 15 minutes or 1 hour (SP or LP data), and the helix screw inside the drum shaft translates them sideways 10" every 24 hours, (the rates are actually metric) making a standard 10" x 36" seismogram. I use inverted 4-oz ink bottles in a bubbler arrangement that provides a month or more of ink to the pens before the bottle has to be refilled. (yes, ink; I have converted all my single channel recorders to write with a fine warm hairpin stylus on fax paper; very reliable, affordable, and capable of a consistent fine line). If you need any info or parts, let me know. I have been pretty successful at rehabilitating the servo chopper, which resonates at 400 hz. The tubes last forever. Re your posting yesterday while you ate a spam sandwhich in persuit of the holy grail: have you seen the Monty Python game for DOS? One seeks out the grail (somewhat undefined) while collecting cans of SPAM, while having to identify a tree that keeps popping up (the game ends if you don't identify the LARCH tree). Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: RADIOTEL Subject: VERTICLE.ZIP Date: Sat, 17 Jan 1998 00:26:37 EST TO: STEVE HAMMOND, ET.ALL I would appreciate if you or someone on the list could EMAIL me "VERTICLE.ZIP or VERTICLE.GIF". Thanks. Jim Allen EMAIL: RADIOTEL@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: watson@................ (Charles Watson) Subject: Re: Computers....UUGGHHHHH! Test...msg Date: Fri, 16 Jan 1998 23:49:51 -0700 During 1997, my ISP was down all of maybe two or three times, all of course during the times I needed it most. Then today, their ftp server crashed. Blast! Just when all the newspapers are calling for their weekly graphic. My patience, however, has tempered throughout the years, imploying every back-up system I could think of to "meet the ol' deadline". Gosh, even did one of those modem to modem transfer today. It wasn't too long ago that it was the norm and the internet was, well, this nebulous thing and the www was something of the future. Still amazes me how far this has come in such a short time, how easy file and graphic transfers have become, web sites and instant info at a click of a button. And listening to Bill Gates talk about procesors doing 100 M calculations per sec in home computers in the next two years boggles my mind. Now if I could just afford one..... Oh, BTW: I passed the month test with the Mammoth Times and they have accepted my proposal for a year contract. Too wigglie to sit still!! Here is a copy of the graphic: http://www.seismo-watch.com/EQNEWS/Newspaper/NewspaperGraphics/MTSeismo.jpg Sorry you can't read the text in this image. T'was in a big hurry when I put it up. I'll see what I can do later. -- ---/---- Charles P. Watson Seismo-Watch _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Doug Crice Subject: ISP ratings Date: Sat, 17 Jan 1998 08:28:01 -0800 Meredith, re ISP's I recently read a summary of comparisons between ISP's. The best provider varied, but IBM and ATT were near the top on all five for user satisfaction. AOL was right at the bottom on all five surveys. Doug Crice _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Seisguy Subject: Re: ISP ratings Date: Sat, 17 Jan 1998 12:39:11 EST In a message dated 98-01-17 11:33:03 EST, you write: > AOL was right at the bottom on all five surveys. > Maybe that's because they have ZERO customer service (just try and speak to a live person there, forget it ) But for the non-techies like me, it's a trade off for having something so damn easy to navagate. Mike O'Bleness Northridge, CA _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: meredith lamb Subject: Colorado Springs meteorite...Part 3 Date: Sat, 17 Jan 1998 11:46:06 -0700 This is a followup to the meteor sighting of Jan 11th 1998, near Colorado Springs, Colorado. USA This is getting juicier all the time...... ........................................................................................... Todays Denver Post article speaks of a local professor speculating on the possibility that this particular meteor MAY actually have been a sloughed off part of the comet Hale-Bobb that whizzed through our neck of the solar system. Reasons for the possibility are that the earth intersected the comets trail last Sunday, and, that the direction of the meteor (southwest to Northeast), is in opposition to most meteors who travel (generally) east to west. No meteorite fragments have been known to have been found at this time. ........................................................................................ Personally...... I would expect that the Colorado Tourist industry likes this kind of thing....even though the guests might be walking around with binoc's, metal detectors, magnetometers and weji boards and perhaps bringing strange bags back with green coke bottles clinking around inside. Somehow, I feel like all this should have been retitled into the past movies of: The gods must be crazy....not I or II but....part 3. Sensible people like myself would find the fragments to be more useful than simply mounting on a museum shelf...I'd mount it as a seismometer mass. (Its the altitude here!) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: shammon1@............. Subject: Re: VERTICLE.ZIP Date: Sat, 17 Jan 1998 11:06:20 -0800 Done-- I sent verticle.gif to your Email at AOL. Regars, Steve Hammond PSN -- San Jose RADIOTEL wrote: > > TO: STEVE HAMMOND, ET.ALL > I would appreciate if you or someone on the list could EMAIL me "VERTICLE.ZIP > or VERTICLE.GIF". > Thanks. > Jim Allen > EMAIL: RADIOTEL@....... > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "David A. Nelson" Subject: Re: Colorado Springs meteorite...Part 3 Date: Sun, 18 Jan 1998 11:16:10 +1200 >Personally...... Sensible >people like myself would find the fragments to be more >useful than simply mounting on a museum shelf...I'd mount >it as a seismometer mass. (Its the altitude here!) U have got to be joking mate i dont call that sensible with fresh meteorite material costing up to US$100.00 per gram u i could sell it and use the money to buy materials for all the seismo great u ever wanted. u obv. dont realise the value of this stuff i buy meteorites and tektites from all over the world its one of the best investment systems u will find. the price of this material is rising at ~15-20% per yr. its price ranging from a few $$ /gram to US$2000 / gram is governed by several factors.... availability of samples; age; composition = stone, stony iron, iron; where it came from eg the moon, asteroids, mars (martian material is the material up to US$2k) if material is from an observed fall this also bumps the price high (fresh fall meteorite) well meredith there it is u gave me a laugh for the morning but i couldnt resist responding. no amount of attitude could presuede me to use 5 to 10 lbs of meteorite as seismometer weight take care have a great day Dave Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson ZL4TBN 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: RADIOTEL Subject: Re: VERTICLE.ZIP Date: Sat, 17 Jan 1998 17:12:37 EST STEVE HAMMOND: Thanks Steve for Vertical.GIF. I appreciate your help. Jim Allen Cerritos, California _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Dewayne & Linda Hill Subject: Re: Colorado Springs meteorite...Part 3 Date: Sat, 17 Jan 1998 23:03:49 +0000 At 11:16 01/18/98 +1200, you wrote: Meredith, Call me I'm ready to go. After all Elbert count is only 250 sq. miles in size. We should be able to find it before sunset. HA HA. Dewayne. >>Personally...... >Sensible >>people like myself would find the fragments to be more >>useful than simply mounting on a museum shelf...I'd mount >>it as a seismometer mass. (Its the altitude here!) > > > U have got to be joking mate i dont call that sensible with >fresh meteorite material costing up to US$100.00 per gram u i could sell >it and use the money to buy materials for all the seismo great u ever wanted. > > u obv. dont realise the value of this stuff i buy meteorites and >tektites from all over the world its one of the best investment systems u >will find. the price of this material is rising at ~15-20% per yr. > its price ranging from a few $$ /gram to US$2000 / gram is governed by >several factors.... > availability of samples; age; composition = stone, stony iron, iron; >where it came from eg the moon, asteroids, mars (martian material is the >material up to US$2k) if material is from an observed fall this also >bumps the price high (fresh fall meteorite) > > well meredith there it is u gave me a laugh for the morning but i >couldnt resist responding. no amount of attitude could presuede me to use >5 to 10 lbs of meteorite as seismometer weight > > take care have a great day > >Dave > > > > >Co-ordinator: >New Zealand >Public Seismic Network > Dave A. Nelson ZL4TBN > 24 Jensen St., > Green Is., Dunedin, > South Is.. New Zealand. > >http://psn.quake.net/dave/home.htm > >IF there indeed are other parallel universes... I can now rest in the >knowledge, that in at least one of them, I am filthy rich and drive a red >Ferrari > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > Dewayne (n0ssy) & Linda (n0uqf) Hill Denver, Colorado USA 39.83569n 105.06270w. Elev 5660ft. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: Re: VBB oscillations Date: Sat, 17 Jan 1998 21:30:16 -0600 (CST) Barry, An easy way to have the VBB system oscillate is to have the connections to the feedback coil reversed; in this condition the thing will bang around in a severe fashion. Of course, I assume that you have explored this possibility. The other place to look is the Td or the time constant of the displacement transducer, which includes any buffer amplifier. It should be reasonably short wrt the mechanical period, ie less than 0.02 seconds (50hz). My experince, though,is that if it is real short, the feedback will oscillate or humm at some low audible frequency. I use a single R-C filter at the output of the displacement detector demodulator, like 2k to 4k ohms into 1 to 4 microfarads (non-polarized, of course). The transfer function will indicate an oscillator if either end of the flat velocity response has an inflection in it. If the damping term zeta is much less than 0.6, the oscillation will be at the effective period, like 20 to 100 seconds, depending on your configuration. If the response has a bump at the short period end, several instabilities are possible due to "out of range" selection of the feedback components, or the value of r is too small. The response should be quite flat. I hope this gets you going. Right now the data here in "the east" is dominated by 6-second storm microseisms because of the severe weather off the east coast. The continental crust acts like a waveguide for the first harmonic of the 12-second surf pounding on the shore. Fortunately they are so monochromatic that they can be reduced on a monitor record by a factor of 100 or so by a passive "twin-T" notch filter. So although my digital data shows them peaking at 20mv, they are less than 1mv on my monitor recorder. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: meredith lamb Subject: E-A speed servo Date: Sat, 17 Jan 1998 23:47:23 -0700 Sean, I find your msg on the Esterline-Angus speed servo's very interesting and with the substitute fax paper, ink stylus approach to be a very practical way around the normal route. The ink and bubbler arrangement you mentioned does have my curiosity though. Ink always seems to vary chemically and from one brand to another...what do you use, get it from, price, address etc. The ink bubbler does present the other mystifier....what is it? Most of my experience is just the simple capillary action pen stuff. Even the ink pens I have used (tubes) vary in their ability to do the job. Could this be also an innovation subsititute you use? I do use simple commercial pens at the moment but this can be changed of course. Anything better is always of interest. The longevity part of your E-A recorders must be due to your careful attention. The speed servo's penmotors part I like best is their resistive plactic flat pot...easy to clean, and relatively frictionless. As far as the tube part, I'am a well known anti- tube type person; my earlier days drove me away from them. Actually my total inexperience is the real culprit I suppose. .....Nah....I'am definitely not a tuber.... E-A came out with a variety of models like all manufacturers. I'am not sure (moot point anyway), but I think the ones you have are these early ~ 5 inch or so linear penmotors. Later they came out with ~10 inch penmotors with the same basic design. Your long time use speaks volumes in regard to reliability. I can visualize your rehab of the choppers...must be delicate. My only look see was to see whats inside along time ago. Actually I have 2 solid state units, model L1101s, and I'am guessing they were made... from the label....in 1977. No manuel or schematics of course. Wrote to E-A some time back, no answer....probably all that stuff was scrapped along time ago. Also have E-A penmotors salvaged from other early digital gizmos. These look inviting for simple (I hope) amps. Endless visualizations of use over time. There was a variety of use for these penmotors besides the regular tube types ranges. Thanks for the offer of info or parts. The info asked above is the present driving curiosity. These E-A penmotors were one of my early most sought after item. Used to visit the Green Building in Golden were they had a variety of operating recording instruments. (GOL). They used several there in the same confiuration that you seem to have there.....over the same type of drums whether single or triple drums. They closed down access some years back, too bad as it was only a block or two from NEIC and their displays. Hmmm, maybe its still accessible but in another part of the building, dunno. Anyway....nothing showed up on the surplus market around Denver till maybe latter 1980's with these E-A penmotors. Getting back to my first views of these...I fell in love...or maybe it was really greed, or envy...which is greed...ok....greed...but it took along time to get one. Brother is a Monty Python fan. Me....I go for the movies of "The Gods must be crazy" part I & II. Don't usually watch anything twice, but these 2 I do. Inspirational don't you think? I suppose they are really a kind of speeded up version of real life dumb things. A person has to laugh at alot of things or else find a way to go nuts from taking things too seriously. Humor is an important part of life, and its best served upon others, if at all possible.... Regards, Meredith Lamb _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: watson@................ (Charles Watson) Subject: Disfunctional USGS "cr" Server? Date: Sun, 18 Jan 1998 09:34:25 -0700 Have you noticed some of the USGS web sites have been slow to respond lately? They all seem to pass through the "cr" server, such as: http://wwwneic.cr.usgs.gov http://gldss7.cr.usgs.gov http://aslwww.cr.usgs.gov http://geohazards.cr.usgs.gov All the other USGS servers pop up quite quickly. You can check them from this URL: http://www.usgs.gov/network/science/earth/usgs.html Something is not working right somewhere and I am wondering if other people are experiencing similar slow connections as well. -- ---/---- Charles P. Watson Seismo-Watch _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: meredith lamb Subject: Meteorite....Part X Date: Sun, 18 Jan 1998 11:05:35 -0700 Dave Nelson, I am really inpressed with your meteorite knowledge Dave. Words like stony, iron, martian,...boy, they really expand the field as I don't know it. HHMmm....wasn't there a variety called Exasperite?..... My daily supermarket tabloid says meteorites have been known to be worshipped in various place in the world. They have also been used for their practical metal content in southeast Asia and the middle East for swords, knives etc. Even the American Indians have displayed some reverence for these objects. Uhh.. .....like tools....Dave? Well....Dave....you're absolutely right....I've decided that it wouldn't be proper for me to use a meteorite as a seismometer mass. This is due dimly to the fact, that at the present......... I don't have any stuff. However Dave,....being as you're a meteorite dealer...and you probably have access to gobs of the stuff, you are probably the best person that I know of, that may have an excess of various meteoritic materials. You probably also have the equipment that can work them into proper shape, via...... diamond tipped power chain saws and the like. Chosing the right material for the job, is one task, I think I'll leave to your descretion....whether its the common stoned variety or etc. The proper word I use previously was altitude,...not attitude... Dave. In this sense, I'am all wrong here. I have the wrong altitude for endeavors of this sort,...whereas your altitude is much better than mine. Anyway...the people of Colorado are probably already overwhelmed with miscellaneous notarity of sorts and don't need any more world wide acclaim. So...Dave...there you have it. An opportunity exists for you to be the first person in the world to use meteoritic material as a mass in a seismometer! Fall on it Dave! Uhhh....fresh meteorite fall?...is that your term Dave? P.S., ...I'am also willing to step aside, and have you make no mention of the fact, that the idea MAY have come from myself. I'll let you start the patent process on this Dave. So....OK Dave....Dave............Dave are you there Dave? :>) Meredith Lamb.....the unskilled meteorortrist _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: Re: Disfunctional USGS "cr" Server? Date: Sun, 18 Jan 1998 12:30:46 -0600 (CST) I had no problem just now with a telnet (FINGER QUAKE) to neis. The "cr" designation means "central region", like there is a "wr" out in CA. and the coast. Regards, Sean-THomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: ink bubler Date: Sun, 18 Jan 1998 12:32:43 -0600 (CST) Meredith, If you saw EA pen drives on triple drums at the USGS in Golden they were probably the same vintage as the ones I am running. Sprengnether Instruments (down the street from the Univ) made about a dozen of them in 1965. (they still make a single component drum recorder, but they use the MFE torque motor, which can be translated easier than drum for helical recording). Three of the EA triple drums went to the new strainmeter observatory in a lead mine south of here that was my first challenge in 1969, and the rest went ??. I got one back several years ago, and also retrieved some complete ServoII units from the Aleutian station at Adak (were part of the strainmeter projuct there that was worring about the geological impact of the mega-nukes "Cannican" and "Milroe" (I think) on Amchitka Island. For pens, I have been getting just the stylus from Sprengnether and fitting it to the EA unit; the drawn down fine part of the tip wears out after several years. Kinemetrics also makes a very fine ink pen that will produce an 0.1mm line; I scored a handful of them when we bought some rehabbed single-drum recorders (like you now see at the USGS) that I converted to hot stylus and FAX paper. Re ink: we get ours from Graphic Controls (I don't have info here) in 8 or 16 oz bottles, with different colors for different stations. A secret about inks is that you should never use water to clean the pens or the feed tube: it makes the ink gell. Use hardware-store alcohol. Because if the fineness of the pen tips, absolute cleanliness is required in handling the ink; latex gloves are also a good idea. The "bubbler" is a large (1.5"sq") plastic block with a 5/8" or so (depends on the cap) round reservoir drilled about 1" into it. The cut-off or drilled through cap of a 2-oz or 4-oz poly bottle is glued upside down into the top of the hole. A smaller hole (1/8") is drilled at an angle from the top into the bottom of the reservior and accommodates the thin metal tube that connects to the long (6") capillary feed tube to the moving pen. To fill the bubbler, the bottle is filled with ink and a large syringe with a tube on it is installed in the small drill hole of the reservoir. Then you hold your breath (and protect everything with paper towels) and quickly invert the bottle of ink into the glued in cap. Ink will bubble into the reservoir, so as you screw the bottle into the cap, the excess ink has to be removed withthe syringe. I initially practiced this with water over a sink; a removeable reservoir avoids the anxiety, but runs the risk of falling off the pivot bar that holds the pen motors. I mount the bubbler directly on the side of the pen motor, where the original ink cartridge was mounted. The level of the ink in the reservoir should be about the same height as the pen tip on the paper. And a final rule about ink pens: they always get AFU after 5PM on Friday, and I hastily fix them WITHOUT latex gloves, and the ink is not exactly washable. Rule 2 is that Mother knows when the ink on a monitor recorder has run out AND when the redundant digital systems have gone OTL, and pushes the button on the quake we have been waiting for. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jim Bone Subject: Re: Meteorortrist? Date: Sun, 18 Jan 1998 10:59:40 -0800 meredith lamb wrote: > :>) Meredith Lamb.....the unskilled meteorortrist > Aw, c'mon Meredith! You can't be that unskilled - anybody who can come up with a title like meteorortrist deserves some kind of an award, especially when it follow a post like yours! I propose you receive the 'socioseismohumorist par excellence' recognition for today, since it's so quiet otherwise. -- Jim Bone _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Canie Brooks Subject: Re: Disfunctional USGS "cr" Server? Date: Sun, 18 Jan 1998 11:06:33 -0800 At 12:30 PM 1/18/98 -0600, you wrote: >I had no problem just now with a telnet (FINGER QUAKE) to neis. >The "cr" designation means "central region", like there is a "wr" >out in CA. and the coast. >Regards, >Sean-THomas I got thru to the world quake list - Noticed a 3.0 for Northern Cal which wasn't on the http://www.scecdc.scec.org/recenteqs/Maps/123-39.html list... The Geysers area.. should have happened about 6:49am PST but the list stops at 5:05 am or so.. (Its now 11:06am PST) > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: kathy mortensen Subject: Re: Disfunctional USGS "cr" Server? Date: Sun, 18 Jan 1998 11:56:51 -0700 Canie Brooks wrote: > > At 12:30 PM 1/18/98 -0600, you wrote: > >I had no problem just now with a telnet (FINGER QUAKE) to neis. > >The "cr" designation means "central region", like there is a "wr" > >out in CA. and the coast. > >Regards, > >Sean-THomas > > I got thru to the world quake list - Noticed a 3.0 for Northern Cal which > wasn't on the http://www.scecdc.scec.org/recenteqs/Maps/123-39.html list... > The Geysers area.. should have happened about 6:49am PST but the list stops > at 5:05 am or so.. (Its now 11:06am PST) > > > > >_____________________________________________________________________ > > > >Public Seismic Network Mailing List (PSN-L) > > > >To leave this list email listserver@............. with the body of the > >message: leave PSN-L > > > > > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L For calif. I use http://quake.usgs.gov/recenteqs/ the 3.0 at the geysers this A.M. was there at 9 A.M PST when I checked!! SKM P.S. hours of uncontrolable laughter from the "Meredith - Dave" soap opera ---- had to print it!!!! ha ha hahaha hahahahah funny stuff!!! _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: Web page update Date: Sun, 18 Jan 1998 18:26:40 -0800 Hi Arie, Great job of constructing your sensors and documenting it. Looking forward to seeing some seismograms soon. Regards, Larry Cochrane Redwood City, PSN At 03:41 PM 1/18/98 +0800, you wrote: >Hi Larry, > >Good news, I've just finished the mechanical constructing phase of the two SG >seismometers and thought you may be interested to see the updated page. > >web page: http://iinet.net.au/~ajbv > >The only thing that's needed to be done is to box and connect your electronics to the >A/D card and repair the GPS micro-controller. I wired the micro-controller to >wrong polarity!! > >Regards > >Arie Verveer >ajbv@............ > > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "David A. Nelson" Subject: Meteorites, to those that responded Date: Mon, 19 Jan 1998 15:34:50 +1200 hi , Meredith, Clark, Dick, and all others interested, Firstly I am not a dealer just a very avid collector of meteorites. they are another branch of my ever expanding collection of rocks, minerals and fossils. With my love of both geology and astronomy the coming together of these was inevidable (SP?) with the collecting of rocks from space. I work closely with one of my university lecturers in the geol. dept. He has a lot of experience with meteorites and also runs the xray fluorescence spectrometer and along with thin section microscope slides we can determine the origin of samples brought to us. its a bit difficult to give a sample amalysis without seeing it in the " flesh" as many meteorites have very similar looks to terresterial rocks. but as some hints and guideslines..... 1) There are 3 main groups (which have many subsections) Irons, Stony Irons and Stones. The Stones have 2 main classifications Chrondrites and Achrondrites. Note: virtually all meteorites will be attracted to a magnet, even the stony ones have up to 15% iron content. stony-irons are up to 90% iron/nickel and of course irons are 100% iron/nickel in composition. Also beware that terresterial volcanics especially basalts can have a high iron contents the ones around my home area are up to 20% , so will happily cling to a magnet. 2) Irons... fresh fallen ones will have a black thin (~1mm) fusion crust, the surface will be generally smooth (no sharp edges unless broken by the ground impact) but uneven, lumpy. in arid regions eg. the australian desert outback or say the Arizona region the meteorite will keep its fresh fall appearence for 1000's of years, but in humid climates the meteorite will oxidise quickly, turning rusty brown with corrosion and can resemble iron concretions found in many sedimentary rocks. If u think u have found and iron meteorite there one undisputable test and that is to slice the sample in a water cooled diamond rock saw, etch the cut surface with acid and polish it. This shows the crystalline structure called the Widmanstatten Pattern which is ONLY ever found in iron meteorites. Be wary the fusion crust on all meteorites that have oxidised a bit can be easily confused with a normal weathering rind found on most exposed terresterial rocks. 3) Chrondrites.... are fine grained stoney meteorites that very closely resemble earthly basalts. The description comes from the small (~1-2 mm diam.) spheres (chrondrules) found through out the rock. A recent sample brought to me for identification fitted the description perfectly and even my lecturer look at it and said " very possible". but the spectrom. analysis showed a good potassium spike which is not found in meteorites. Instead the sample had all the attributes of out local basalts in composition. Oh well... good try :)) 4) Achrondrites ... as the name suggests doesnt have the chrondrules present. They are also much coarser, ranging from the look of a granite in crystal size and structure to large coarse lumps... brecciated rock. The stoney meteorites have a composition of ~30% pyroxene, ~40% olivine, ~10% plagioclase and ~5 - 20% nickel-iron. Finally there is one other conclosive test for all meteorites or would be ones and it can be done in only a handful of labs around the world. When the meteor is in space it is constantly being bombarded with cosmic rays this produces substantial 26Al isotope. If these fragments have had cosmic exposures of at least a few million yrs, then their surfaceswill reach saturation in 26Al production (t1/2 = 0.7 Myr). After falling to earth, the atmosphere shields the meteorite from further 26Al production. and the decay of this isotope can be used to determine how long it has been on earth. a WWW site of interest... these ppl also will do possible meteorite tests on samples sent to them they require only a thumbnail size piece. http://eps.unm.edu/iom/ well guys not exactly seismology but damn interesting anyway cheers Dave Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson ZL4TBN 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: step calibration Date: Sun, 18 Jan 1998 22:34:39 -0600 (CST) Barry, The step response, either due to a current in the calibration coil or the lifting of a small test mass, contains all frequencies of interest. It is also a change in force: aka acceleration. So to compare it with the velocity response predicted by the transfer function, isolate the data segment and take the FFT of it (I use MCADs complex FFT), and then divide the FFT values through by omega**2 (once is because of the step, the second is because the output voltage is velocity and the input is acceleration). The resulting response should look like the transfer function within the limits of your digitizer. An example of this is in figure 10 (I think; I rearranged them) of my web page of figures and schematics. The agreement is good from 10 seconds to 500 seconds. Local and microseismic noise dominates the spectrum at less than 10 seconds. I could use a larger step pulse, but my digitizer is limited to 12-bits. My digitizer is also one sample/second, so the nyquist (minimum useful frequency) is 2 seconds. I have to rely on my monitor recorder for short period data, like local events. (Teleseisms are generally more interesting to me.) (I am thinking of a way of putting the MCAD source for these figures out in a directory that you can download from and then open with your MCAD; the data file (xxx.prn) would also have to download). The calibration coil can also be used with a function generator to input sine waves of constant P-P current. The output amplitudes are then measured (either digitally or on a monitor recorder) and divided by their respective omega, and the resulting plot is the velocity response. If you calibrate the calibration coil (weight to balance a given current), you can calculate the absolute magnification of the instrument. I need to do this on the prototype here and then post it to show the details. A shake table is a rare luxury; the AFOSR paid for the one in our department back in the 60s. It is driven by a 5hp hydraulic system (to handle the Big Benioff seismometers that weigh 400 lbs), and operates from DC to 40 hz, 0.1 to 100 microns, with separate vertical and horizontal tables. We generally let anyone use it. So we need some more earthquakes to test our instruments. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Walt Williams" Subject: Re: zero length spring Date: Sun, 18 Jan 1998 12:20:18 +0000 Hello Charles, Thank you. Walt Williams, 98.01.18 dfheli@.............. ================================ ------- Forwarded Message Follows ------- Date: Thu, 15 Jan 1998 13:47:22 -0800 From: "Charles R. Patton" Reply-to: PSN-L Mailing List Organization: Western Digital To: PSN-L Mailing List Subject: Re: zero length spring Check out the URL: http://www.lacosteromberg.com/detail.html#physics The site is LaCoste-Romberg Co. and the particular URL is pointing at a section of their manual which describes the theory and construction of the zero-length spring and LaCost suspension in a gravity meter. Back up a bit, and you can get a full education on gravity meters they manufacture. I'm amazed. This is the first site I have come across that puts their equipment manuals on line. Charles R. Patton patton@......... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Walt Williams" Subject: zero length spring Date: Sun, 18 Jan 1998 22:10:24 +0000 Sean-Thomas, Thank you. Walt, 97.01.18 =========================================== ------- Forwarded Message Follows ------- Date: Wed, 14 Jan 1998 23:31:15 -0600 (CST) From: S-T Morrissey To: psn-l@............. Subject: zero length spring Reply-to: PSN-L Mailing List Walt, Regarding "zero length" beahvior of a spring. For an ordinary spring, as it it stretched, the change in length is proportional to the force applied. If you attach a linear dial an put it in a box and step on it, it will tell you how well you prospered fron the holiday feasting. ie Hooks law: F = k *(l - lo), where k is the spring constant (force/unit length), l is the length with the force F applied, and lo is the initial length. When such a spring is used in a vertical seismometer, this means that the restoring force changes as the boom moves, making the sensor non-linear. This was solved in the 30s by the LaCoste suspension that devised a spring such that at a specific length the change in force with change in length became zero. That is, if lo = 0, so F = k*l, then F is constant. So any minute acceleration will move the mass in a linear fashion. So when such a spring is made, namely by twisting the wire (or quartz fiber in gravimeters) as the coil is wound, the spring ends up forcibly closed: it takes an initial force to open it. I won't go into the math to determine the constants, but at some opened length, lo becomes 0. With the leaf spring I use, this occurs at about a 5" opening, and is evident when the spring is installed and the opening adjusted. At one point, the boom will not stay balanced, but floats either up or down with instability (aka an infinite period). So I increase the opening slightly, and the period becomes stable. A stable period is essential for a well defined transfer function. Regards, Sean-Thomas !p _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Mb magnitude calculation Date: Sun, 18 Jan 1998 22:20:39 -0800 Hi, I'm working on adding Mb magnitude calculation to WinQuake. Does anyone know off hand if Mb is calculated using a vertical and/or horizontal sensor? Thanks.... -Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Bob Fryer Subject: Re: Computers....UUGHH! & precursors Date: Mon, 19 Jan 1998 00:52:18 -0800 Hey Charles, Great! But have you checked your chair? Some of the EQ sensitives in Mojave desert, etc. are reporting ant infestations. Apparently the ants are fleeing telluric currents. Can anyone help me with any of the items listed below? Take care, Bob Fryer >Oh, BTW: I passed the month test with the Mammoth Times and they have >accepted my proposal for a year contract. Too wigglie to sit still!! >Here is a copy of the graphic: >http://www.seismo-watch.com/EQNEWS/Newspaper/NewspaperGraphics/MTSeismo.jpg > >Sorry you can't read the text in this image. T'was in a big hurry when I >put it up. I'll see what I can do later. > >---/---- >Charles P. Watson >Seismo-Watch ------------------------ Hi gang, Just received (out of the blue) the item below from Japan; apparently from a member of the team doing the work. For the present, I have removed the name and addresses of the sender. Some of the materials seem to be available only in Japanese, while others appear to be in German, Swiss or ??? -- "Naturwissenschaften." Some of the undecypherable material may have been in Kanji (Japanese). If anyone has access to English versions, please share! Thanks, Bob F ------------------------------------ Sun Jan 18 17:40:05 1998 Date: Mon, 19 Jan 1998 10:39:25 +0900 To: bfryer@............ From: ********* <*****@...................> Subject: Earthquake legends Followings are a list of publication in this field. We are involved in thes research after the Kobe earthquake. Reprints are available on request. [Signed.] 1996 96-1 Ikeya, M. and Takaki S. (1996): Electromagnetic model of a fault for earthquake lightnings (EQLs). Jpn. J. Appl. Phys. 35, L355-L357. 96-2 Ikeya, M. Takaki, S. and Takashimizu, D. (1996a) Electric shocks for seismic animal anomalous behaviors (SAABs). J. Phys. Soc. Japan 65, 710-712. 96-3 Ikeya, M. and Takaki, S. (1986): Seismic electric signals (SES) and animal anomalies. J. speleol. Soc. Japan 20, 38-47. 96-4 Ikeya, M., Huruta, H., Anzai, H. and Kajiwara, N. (1996b): Electric field effects on rats and sparrows for seismic animal anomalies (SAAs). Jpn J. Appl. Phys. 65, 4587-4594. 96-5 池谷元伺(1996):地震に伴う電磁現象と動物の異常行動、科学（岩波書店）6 6 巻　408-418. Ikeya, M. (1996): Electromagnetic phenomena and anomalous animal behaviors accompanying earthquakes. Kagaku 66, 408-418 (in Japanese). 1997 97-1 Ikeya, M., Takaki, S., Matsumoto, H., Tani, A. and Komatsu, T. (1997): Pulsed charge model of a fault behavior producing seismic electric signals. J. Circuit, Systems and Computers 7, 153-164. 97-2 Ikeya, M., Kinoshita, Y., Matsumoto, H., Takaki, S. and Yamanaka, C. (1997): A model experiment of electromagnetic wave propagation over long distances using waveguide terminology. Jpn J. Appl. Phys. 37, L - L . 97-3 Ikeya, M. and Matsumoto, H.(1997): Reproduced earthquake precursor legends using a Van de Graaff electrostatic generator: Candle flame and dropped nails. Naturwissenschaften 84、539-541 (1997)　. 97-4 Ikeya, M. and Q. Huang (1997): Earthquake frequency and moment mragnitude relations for mainshock, aftershocks and foreshocks: Theoretical b-values. Episodes 20, 97-5 Sasaoka, H., Yamanaka, C. and Ikeya, M. (1997): Measurements of electric potential variation by piezoelectricity of granite. Geophys. Res. Letters 97-6 Huang, Q. and Ikeya, M. (1997): Electric field effects on animals: Mechanism of seismic anomalous animal behavior (SAAB). Earthquake Research in China. 97-7 Huang, Q. and Ikeya, M. (1997): An experimental approach to the electromagnetic phenomena associated with earthquakes. Ionics . 97-8 Ikeya, M., Komatsu, T., Y. Kinoshita, Takaki, S., Teramoto, K., Inoue, K., Gondou, M. and Yamamoto, T. (1997): Seismically-induced anomalous animal behavior (SAAB): Electric field before earthquakes at Kobe-Oji Zoo and Izu-Atagawa Tropical Banana-Alligator Garden. Episodes. 　 97-9 　池谷元伺（1997）：安政見聞録を正す（1）、エコＪ　地震と防災１巻 No.6,　 70-74. 1998 98-1 池谷元伺（1998）：地震の前、動物はなぜ騒ぐのか、ＮＨＫ出版ｐｐ265 　（印 刷中） Ikeya, M. (1998): Why Do Animals Behave Anomalously Before Earthquakes, NHK Publisher. in Japanese in press. (to be published 20 Feb. 25 , 1998) 98-2 Ikeya, M., Matsumoto, H. and Q. Huang (1998): Aligned silkworms as seismic animal anomalous behavior (SAAB) and electromagnetic model of a fault: A theory and laboratory experiment. Acta Seimology Sinica 20, in press. Ikeya, M. and Matsumoto, H.(1997): Reproduced earthquake precursor legends using a Van de Graaff electrostatic generator: Candle flame and dropped nails. Naturwissenschaften 84、539-541 (1997)　. Some mysterious earthquake precursor phenomena depicted in Japanese legends and also reported retrospectively in the Kobe Earthquake in 1995, have been reproduced in laboratory experiments using a Van de Graaff electrostatic generator. This suggests that pulsed electric charges appeared in the epicenter area. Folk stories of a reverse U-shaped candle flame on an altar and of iron nails dropping from a magnet were explained by the appearance of free charges produced by the depolarization of piezoelectricity for quartz grains in granitic rocks during seismic stress changes. * * * * * * *^ * *^ * * * * * * * ^ * * * * * ^ * * * Osaka 560, Japan ^ * * * * * ^ * * * * * * * ^ * * * * ^ * * * * ----- earthquake WARNING research ----- --- animals, people, scientific evidence --- --- http://www.teleport.com/‾bfryer --- _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: watson@................ (Charles Watson) Subject: Re: ant behavior Date: Mon, 19 Jan 1998 07:54:51 -0700 Bob Fryer wrote: > > Hey Charles, > > Great! But have you checked your chair? Some of the EQ sensitives in > Mojave desert, etc. are reporting ant infestations. Apparently the ants > are fleeing telluric currents. > My chair looks fine. I am not convinced ant behavior can indicate precursors to large earthquke activity. -- ---/---- Charles P. Watson, Consulting Geologist Advanced Geologic Exploration Seismo-Watch / Earthquake Information Services Voice: 702-852-0992 / Fax: 702-852-3226 Office Location: 39.43N 119.71W mailto:watson@................ http://www.seismo-watch.com _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "frank murray" Subject: RE: Computers....UUGHH! & precursors Date: Mon, 19 Jan 1998 08:25:46 -0800 bob fryer asks: > > Can anyone help me with any of the items listed below? and though you probably did not mean as far below as where this is posted: > ----- earthquake WARNING research ----- > --- animals, people, scientific evidence --- > --- http://www.teleport.com/‾bfryer --- i think some help there might be needed...on your site you have a long interview with a lady named charlotte who claims to predict earthquakes, volcanic eruptions, etc with 98% accuracy...from the interview: >Q. Are you ever wrong? >A. I'm running 98% (accurate). I wish I was wrong a lot of times. >That bothers me. incredible if true...but the interview also states (charlotte speaking): >Now the quake of February the 13th (1981), in Elk Lake, Washington -- I >think it was measured as 7.1 -- hit at 10:10 that evening. (snip) >I headed to the doctor's office and was checked over and found out I was >okay. Then I notified Colorado, U.S.G.S., and I said, "There is going to >be a major quake, probably Washington, within 72 hours, of a 7 or higher." (snip) >Just six hours later a 7.1 quake hit Elk Lake, Washington, near the volcano. here's the cnss catalog data for that quake (time in UTC): >date time lat long depth mag >1981/02/14 06:09:27.21 46.3493 -122.2360 7.28 5.20 cnss says it was a M5.2 quake, not a M7.1...in short, the listed magnitude of the quake is between one and two percent (1% - 2%) of the magnitude that she claims...where's the other 98% of the magnitude from??...perhaps the same place as her: >...I'm running 98% (accurate). perhaps you might post a warning on your website for any who might otherwise take seriously her claims... cheers, frank for my electronic college proposal: http://home.att.net/‾fjtmurray/ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: watson@................ (Charles Watson) Subject: [Fwd: Volcano Tours in 1998] Date: Mon, 19 Jan 1998 15:30:14 -0700 FYI -- ---/---- Charles P. Watson, Seismo-Watch PLEASE DO NOT USE REPLY TO RESPOND TO THIS MESSAGE ----------------------------Original message---------------------------- ________________________________________________________________________________ VOLCANO TOURS in 1998 Volcano Tours, a Rhode Island-based company, offers a variety of excursions to the volcanic regions of the Earth in 1998, led by local volcanologists or scientists with experience in the region. Tours in 1998 include: Costa Rica: Departures on March 5 to 15 1997, and November 5 to 15 1997. Leaders are Guillermo Alvarado and Haraldur Sigurdsson. This tour includes Poas, Miravalles, Arenal, Cerro Chopo, Cerro Chato, Turrialba and Irazu volcanoes. Italy: Departures 1 to 15 May 1998, and 9 to 21 October 1998. Leaders are Haraldur Sigurdsson (spring) and Mauro Coltelli (fall). Tour includes Pompeii, Mount Vesuvius, Herculaneum, Campi Flegrei, Monte Nuovo, Stromboli, Lipari, Vulcano and Mount Etna volcanoes. Indonesia : Departures are June and August 1998, Leaders are Haraldur Sigurdsson and the Indonesian geologist Sutikno Bronto (June) and Steven Carey and Sutikno Bronto (August). Tour includes a cruise of the Krakatau volcanic islands in the Sunda Straits, Anak, Sertung and Rakata, Merapi volcano, Yogyakarta, Dieng Plateau, Borobodur, the island of Bali, including Batur, Agung and Ubud. Iceland: Departures are 4 to 18 July 1998, 8 to 22 August 1998. Tour leaders are the Icelandic geologists Gudrun Larsen and Haukur Johannesson. Tour includes: Blue Lagoon, Reykjanes peninsula, Vestmannaeyjar, Heimaey,Thingvellir, Laugarvatn, Geysir, Gullfoss, Hekla volcano, Laki fissure, Eldgja fissure, Landmannalaugar, Sprengisandur desert, Myvatn, Krafla, Tjornes, Asbyrgi, Dettifoss, Akureyri, Kjolur, Hvitarvellir. For details and a brochure, contact Toni Rottenberg at Volcano Tours at 7 Wildflower Road, Barrington RI 02806; tel. 800-923-7422, 401-247-0038; fax 401-247-0270; or check their web site at http://www.volcanotours.com ---------------------------------------------------------------- Haraldur Sigurdsson, Professor Graduate School of Oceanography University of Rhode Island, Narragansett, RI 02882-1197 USA Tel. 401-874-6596; home: 401-423-0247; Fax: 401-874-6811 e-mail address: Haraldur@................... __________________________________________ From: Larry Cochrane Subject: New WinQuake beta release Date: Mon, 19 Jan 1998 15:55:33 -0800 Greetings, I released a new beta version of my WinQuake program. Both 16 and 32 bit version are available. The 32 bit version, for Win95 and NT, are at the following URLs: ftp://ftp.seismicnet.com/users/psn/software/wq32b4.zip or ftp://psn.quake.net/software/wq32b4.zip and the 16 bit version can be download at: ftp://ftp.seismicnet.com/users/psn/software/wq16b4.zip or ftp://psn.quake.net/software/wq16b4.zip Please and use the ftp.seismicnet.com address if possible. Heres what's new. Map Feature; This new feature uses the default Web browser loaded on the system to display either the station and/or the event location using the Xerox map system at http://pubweb.parc.xerox.com/map. Under the View menu item you will see three new menu items. One displays both the event and station location and the others display either the station or event. This feature is used one other place. In the Report dialog box you will see a new button called "View On Map". This button will view the currently selected item in the report list. If the View menu items, or the Report button, are disabled then WQ was unable to find a default browser on the system. This is really a neat feature and I use it often, wish I could say I thought of it... Mark Halliday, our Ben Loma, California PSN station suggested it. Thanks Mark! FFT; When Edward Cranswick was out here for the AGU meeting in December he helped me add some new features to the FFT section of WQ. You can now change the sloop of the filtering by specifying the number of poles of filtering to use. You can also save a default freq. and number of poles to use for each of the filter types. WQ can now display the amplitude of the freq. spectrum in Log format. You can change between Log and linear by turning on/off the Option menu item "Log-Y". Thanks for the help Edward! PEPP Data set; WQ can read PEPP (Princeton Earth Physics Project) data sets. A data set contains one or more event files in one file. If you select a data set using the File Open dialog box, the list of event/dataset files will change to a list of event files in the data set. You can then select one or more files to open from there. When you select a PEPP data set the Update button title will change to "All Files". Selecting this button will re display the event files and data sets in the current selected directory. PEPP to SAC Binary Save; I added the ability to save PEPP files as SAC binary files. I also fixed a bug when you tried to save a PEPP file as a PSN file. P and S Location; When you first display an event file, and the P and S markers locations have not been saved in the header information and the event location and time of origin info is known, WQ will try and locate the P and S markers using the current default JB tables. HTML Documentation; One of the things I need to do is come up with some better documentation for WQ and SDR. What I want to do is create a set of HTML pages for both software programs. Now that WQ can use the systems web browser I have changed how the Help menu item works. Before it would open a text file and display it using Notepad. Now it send a URL, a local file in the root WQ directory, that the browser can display. Currently I converted the current doc file I have to a simple web page. In each of the WQ zip files you will see either winquake.html (32 bit release) or winquake.htm (16 bit). After unzipping the file you should copy the html file over to the directory that you use for WQ. Upgrading; If you haven't loaded WinQuake on your system, you first need to install the 2.4 release available at http://psn.quake.net/software. The beta release only has a new EXE file, and some other data/html files, so by using the install/setup program in the 2.4 release your system will have all of the other files need to run WQ properly. The first thing to do is make sure your not running WinQuake. If its running you will need to exit the program. You can't copy the new EXE file over to the working directory if WQ is running. After unzipping the beta release files into a temporary directory, copy all of the files over to the WQ directory. The default directory for WQ is c:¥winqk32¥, for the 32 bit version, and, c:¥winquake¥ for the 16 bit version. Thats it. Please let me know if you run into any problems with the new features (or old ones...). -Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: meredith lamb Subject: New Winquake map featue Date: Mon, 19 Jan 1998 20:47:21 -0700 Larry & Mark; Your new station & quake epicenter feature works great! Very impressive indeed! Thanks, Meredith Lamb _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: seismometer pier Date: Tue, 20 Jan 1998 00:24:57 -0600 (CST) Dewayne, The pad for a seismometer should be as large in area as practical, especially for a horizontal with its' tilt sensitivity. It needs to be massive but not necessarily sturdy, since the seis is rather lightweight. So if I was to make one in a crawlspace, I would just level a spot and form it up with 2x4s for at least 24x36" and then mix enough sacrete to fill the form and level it. For the "pier" in my basement here, I then stacked up and grouted together two layers (16" height) of some standard 8x8x16" concrete blocks to raise the instrument surface so working on the sensor isn't such a backache. I topped the blocks with 24" sq patio pavers, then grouted 12" ceramic tiles on top to provide a very smooth surface to mount the sensor. I don't know how much headroom you have in your crawlspace. Regarding insulation, mass and thickness is important: I have tried alternating layers of drywall and styrofoam, sealed together with duct tape, in a 4" thick sandwhich. The top and front side need to be easily removeable, so they fit with a dovetail arrangement that prevents drafts. For some amount of temperature control, you need something with a thermostat that is sensitive, or thermal cycling will be a problem. A readily available item is a water heater for an aquarium; it has to operate submerged in H2O, but a gallon jar will do. They have very sensitive thermostats. The lowest wattage will probably do. I use a radio shack indoor-outdoor digital thermometer to keep tabs on the temperature. Additional jugs of water inside the seismometer case help recovery after the cover is opened to adjust the instrument. Regards, Sean-THomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: Re: Mb magnitude calculation Date: Tue, 20 Jan 1998 00:47:35 -0600 (CST) Larry, The Mb magnitude is usually calculated from the vertical component body waves. The reason for this is that generally the propagation of the vertical energy is not as dependent on the relationship of the earthquake source mechanism to the receiver (aka seismometer) as is the horizontal energy. The horizontal component of the shear wave propagates at right angles to the direction from the source. This is the reason why the network we had in the Aleutians consisted of only a vertical and an EW sensor at all the stations: all the quakes were in the trench south of the islands, so a NS sensor would provide little data. This is also the reason that most networks of stations are mostly vertical component sensors, although all three components are preferred if funding allows. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: bob@................. (Bob Hammond (USGS-AVO Geophysicist)) Subject: Re: Mb magnitude calculation Date: Tue, 20 Jan 1998 10:19:17 -0900 Larry, Mb is calculated from a vertical sensor. Bob _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: lahr@.................. Subject: period versus dimension Date: Tue, 20 Jan 1998 14:06:52 -0700 (MST) Hi Sean, You sure have bumped up the level of knowledge on the PSN! Thanks for all of your efforts. I'm not following many of the details, but am saving the Email for the day, who knows when, that I will try to build a seismometer. I had one question about a recent post: You write: "But a real physical pendulum has distributed mass, and Tn= 2*pi*sqrt(k/(M*g*r)), where k is the moment of inertia, r is the distance from the pivot to the Cm (center of mass), and M is the mass. So now the L of a simple pendulum is equal to k/(m*r), which is called the "reduced" pendulum length. What you were observing as you increased the mass was that the moment of inertia k was increasing, lengthening the period. But the period can never be longer than that of a simple pendulum of the same length." I'm not so sure about the last sentence above. From your equation, as r approaches zero the period approaches infinity. This would be equivalent to suspending a slightly off-balance tire by its axle, with the axis of the axle horizontal. The period would not be limited by the diameter of the tire. JCLahr ################################## John C. Lahr ################################# Seismologist ################################ U.S. Geological Survey ############################### Geologic Hazards Team, MS966 ############################## PO Box 25046 #############################/############################## ############################/############################### Denver, Colorado 80225-0046 ################################ Phone: (303) 273-8596 ################################## Fax: (303) 273-8600 ################################### lahr@........ ##################################### http://www.aeic.alaska.edu/lahr _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Walt Williams" Subject: Re: A Lunchpail Amateur Seismologists Best Story Date: Tue, 20 Jan 1998 15:08:10 +0000 Hello All, A couple of years ago, I 'felt' an earthquake. It was about 04:30 am. In my sleep, I heard a loud bang noise, a sound like rumbling, maybe 15 Hz. Then all hell broke loose. In the bedroom, in the dark I went to the dresser where I always put my glasses and reached for them. But, every time I did so, the dresser was not in the right spot, so I would miss. Finally, by reaching around the dresser (small), I was able to stabilize the dresser enough to grasp my glasses. I put on my shoes and ran into the den, the lights in there were on. We have a beam which is two feet high by one foot thick and is the length of the ceiling. This was moving up and down six to ten inches, 15 to 20 times a minute, the floor was moving in waves. The TV set flipped off it's pedestal, the book rack was emptying, it was really surreal! I exited the house through the glass sliding door in the den. About now the power went out. The earth stopped moving. It had moved for about fifteen seconds. It was very strange outside, absolute animal silence. No dogs barking, no cars moving, and yet at the same time the stark stillness was intermingled with car alarms annunciating everywhere. And in the distance one could hear and see blue and purple flashes of light and the sharp reports of power-line transformers shorting and popping! As far as I could see, in any direction the city was dark, and sky was pulsating with purple flashes. Standing in the yard, I looked around and discovered my lady was not with me, gads, who would suspect she would stay in there? I assumed she was right behind me?! I must tell you, it took all my courage to go back into the house. I stood there in the side yard maybe ten or fifteen seconds, and went back into the house, then I heard the second and much louder bang, then a sound like a roaring diesel train engine and the quake started again. This time I went through the kitchen, in the dark, it was real crunchy in there, I was wondering, "what the hell is this?", later I discovered it was all of our stemware. In the hallway, half walking and crawling, as the floor and walls were moving, I made it back to the bedroom. Dolly, my girl, was sitting there, telling me it was safer in the house, I pulled her off of the bed just as the wall-unit-book-rack collapsed on to the bed where she had been. The ceiling fan also came down, the windows were cracking. The earth was moving violently up and down, with side to side oscillations at this time; very destructive motion. We exited the house through front door. It took several attempts to open it; the frame was deforming and vising it shut, I had to synchronize with the rhythm. Outside, it was fantastic, it is amazing to see just how plastic the earth is. The street, our driveway and yard was moving in disjunctured waves. This quake persisted about fourty five seconds, the first was about fifteen seconds duration with a fifteen to twenty second pause in between. It was during the second the freeways and apartment buildings collapsed in and around Northridge. This was not my first quake, I also experienced the Sylmar California Quake, but it was much less destructive. After some moments we realized everyone on our block was standing in their front yards and most were naked. When it really gets rough, all one needs is glasses and shoes! My girl is always prepared, else we would have starved, if not for her earthquake preparedness preparations. We had - food, water, camping / cooking utilities, gas lamps, butane tanks and batteries. This event was called the Northridge Quake, (LA suburb, California, USA). Every house within seventy five miles suffered at least $20,000 US Dollars damage. Many were red tagged as they were unsafe to enter. The majority of the Hispanic population would not enter their residences and were living in the city parks in US Government supplied tents. In our neighborhood, Canoga Park, telephone service was restored in about five days, electricity was restored in 14 days, gas - thirty days, and water - 20 days. My friend, who lives in Northridge, near where the freeways collapsed, did not have any services for several months. Periodically I see postings relating people's earthquake experiences, I hope you do not mind my sharing of this experience with you. The experience was awesome, fearsome and incredibly interesting. The power of the forces of physics in action can be truly mind boggling. Best Regards, Walt Williams, 98.01.19 dfheli@.............. Canoga Park, (LA suburb), California USA ========================================================= ------- Forwarded Message Follows ------- Date: Wed, 14 Jan 1998 15:14:56 -0800 To: PSN-L Mailing List From: Karl Cunningham Subject: Re: A Lunchpail Amateur Seismologists Best Story Reply-to: PSN-L Mailing List Meredith -- Very interesting story. I've been very curious if anyone has been able to "feel" a teleseismic event, and you did! Another curiosity this brings to mind is to make a "perpetual motion" machine -- a high-Q mechanism resonant at 6-seconds to pick up the background noise. The idea is to have this thing sitting there constantly moving. Perhaps a rocker with a strategically placed mass could be made into such a thing. I guess my best story is about going to Landers a few days after the big event and seeing boulders the size of a two-car garage that had tumbled down a hill, and seeing the almost 8-meter horizontal and 2.6-meter vertical offsets along the fault. There were ruptures everywhere on little fault strands going this way and that. I was standing about 5 meters away from the fault near the area of greatest offset when a M5+ aftershock occurred. I didn't feel anything, but heard a VERY low frequency rumble -- perhaps 15Hz and very loud. It sounded as though the nearby mountains were talking. I detected no movement of the fault and saw no dust, though. Karl Cunningham La Mesa, CA. PSN station #40 karlc@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ralvarez@........ (Raul Alvarez) Subject: seismo triangulation Date: Tue, 20 Jan 1998 17:15:48 -0700 (MST) Hi Group, Just been thinking on the way home tonight (it's a long way up this mountain, have lots of time to think!:-) ), about the possibility of using 3 seismos situated about 200+ meters apart in a triangle to determine signal direction. Anyone have comments on feasability? Is there enough delay over 200+ meters to detect time/phase shift? I'm fairly new at this, so am I pipedreaming? Raul ‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾ ‾ ‾ ‾ "My dreams are the seeds of my reality, ‾ ‾ nurtured in the womb of my soul" ‾ ‾ RJA, 1985 ‾ ‾ ‾ ‾ ‾ ‾ Raul J. Alvarez ‾ ‾ Bellvue, Colorado ‾ ‾ e-mail ralvarez@........ ‾ ‾ homepage www.frii.com/‾ralvarez ‾ ‾ "The Renaissance Experimenter" ‾ ‾ experimenter in: ‾ ‾ Radio and Optical Astronomy, Seismology, Weather, ‾ ‾ Computers, Instrumentation and Neat Stuff! ‾ ‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "frank murray" Subject: RE: A Lunchpail Amateur Seismologists Best Story Date: Tue, 20 Jan 1998 16:50:26 -0800 > -----Original Message----- > From: Walt Williams [mailto:dfheli@............... > Sent: Tuesday, January 20, 1998 7:08 AM > To: PSN-L Mailing List > Subject: Re: A Lunchpail Amateur Seismologists Best Story > This event was called the Northridge Quake, (LA suburb, California, > USA). > Every house within seventy five miles suffered at least $20,000 US > Dollars damage. absolute nonsense...draw a circle of 75 mile radius around the epicenter and you find that it encloses santa barbara, bakersfield, san bernadino, and all of los angeles down to around laguna beach... excuse me...perhaps i'm jumping to conclusions...perhaps it's just that the media misreported that M10.4 quake at northridge... jeers, frank _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: Re: period versus dimension Date: Tue, 20 Jan 1998 19:27:14 -0600 (CST) John, The r of a physical pendulum is the radius from the point of rotation to the center of mass, and the moment of inertia is k = M*(r**2), and the period T = 2*pi*sqrt(k/M*g*r). If all the mass is at the end L of the pendulum, r = L, which is a simple pendulum, and the period T = 2*pi*sqrt(L/g). As the center of mass moves towards the pivot, r decreases, and the equivalent pendulum length l = k/Mr decreases. In the simple condition that all of M is always at r, l = k/Mr =(M*r**2)/Mr = r. So as r becomes shorter, T also decreases toward zero. The original question posed was whether adding mass at the end of the pendulum will increase the period. It does to the extent that k increases, up to the point that virtually all the mass is at the free end and r = L, and the maximum period of a simple pendulum is obtained. If you have time to follow up on the homemade seismometer, I would appreciate your comments about my web pages on it at: http://www.eas.slu.edu/People/STMorrissey/index.html I have also submitted an abstract for the SSA meeting regarding the calibration of the instrument. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: Re: period versus dimension Date: Tue, 20 Jan 1998 19:27:14 -0600 (CST) John, The r of a physical pendulum is the radius from the point of rotation to the center of mass, and the moment of inertia is k = M*(r**2), and the period T = 2*pi*sqrt(k/M*g*r). If all the mass is at the end L of the pendulum, r = L, which is a simple pendulum, and the period T = 2*pi*sqrt(L/g). As the center of mass moves towards the pivot, r decreases, and the equivalent pendulum length l = k/Mr decreases. In the simple condition that all of M is always at r, l = k/Mr =(M*r**2)/Mr = r. So as r becomes shorter, T also decreases toward zero. The original question posed was whether adding mass at the end of the pendulum will increase the period. It does to the extent that k increases, up to the point that virtually all the mass is at the free end and r = L, and the maximum period of a simple pendulum is obtained. If you have time to follow up on the homemade seismometer, I would appreciate your comments about my web pages on it at: http://www.eas.slu.edu/People/STMorrissey/index.html I have also submitted an abstract for the SSA meeting regarding the calibration of the instrument. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Stephen Caruso Subject: Re: A Lunchpail Amateur Seismologists Best Story Date: Tue, 20 Jan 1998 20:34:43 -0500 (EST) That is what this list is all about, truly a lucid experience! Well written Walt. STEPHEN CARUSO CET KB8UGH "Coincidence is a shortsighted mental delusion" _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: Re: seismo triangulation Date: Tue, 20 Jan 1998 19:46:17 -0600 (CST) Raul, Seismic wave velocities are of the order of 2 to 6 km /second, depending on the wave type. So even a slow surface wave at 2000 m/sec would zip across your 200 m array in 0.1 second. Small arrays have been used for azimuthal data, but they are usually at least a kilometer on a side, or 10 km for p-waves. There used to be an array operated by SLU to track hurricanes, since they produce large 3 to 6 second microseisms. But the azimuth was determined by phase coherence across the array to get a direction to the source. Several such arrays could locate hurricanes as they approached the coast. Maybe a better plan would be to link up the Denver area PSN stations into an array. Another way we guess at teleseismic locations is by determining the distance using S-P times, then consulting a great circle map of the world centered on us, with distances drawn in degrees. If an event is 35 degrees away from us, the only probable earthquake source region it could have come from is Columbia. A 50 degree distance has two possibilities, Northern Chile or the Eastern Aleutians. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: S-T Morrissey Subject: Re: seismo triangulation Date: Tue, 20 Jan 1998 19:46:17 -0600 (CST) Raul, Seismic wave velocities are of the order of 2 to 6 km /second, depending on the wave type. So even a slow surface wave at 2000 m/sec would zip across your 200 m array in 0.1 second. Small arrays have been used for azimuthal data, but they are usually at least a kilometer on a side, or 10 km for p-waves. There used to be an array operated by SLU to track hurricanes, since they produce large 3 to 6 second microseisms. But the azimuth was determined by phase coherence across the array to get a direction to the source. Several such arrays could locate hurricanes as they approached the coast. Maybe a better plan would be to link up the Denver area PSN stations into an array. Another way we guess at teleseismic locations is by determining the distance using S-P times, then consulting a great circle map of the world centered on us, with distances drawn in degrees. If an event is 35 degrees away from us, the only probable earthquake source region it could have come from is Columbia. A 50 degree distance has two possibilities, Northern Chile or the Eastern Aleutians. Regards, Sean-Thomas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: meredith lamb Subject: Northridge...from a long distance away Date: Tue, 20 Jan 1998 20:08:11 -0700 Walt Williams, Thank you for your story...it was a strong story of a strong quake. It was covered and pre-empted alot of regular tv programming for that day in Denver. It was not pretty watching the telecast switching from spot to spot commentary to helicopter overviews of destruction and shots of injured and the dead from it. For anyone involved...it would have been very tough, for quite some time afterwards also. Too me, any quake story is a part of all quakes and that is why we all share this interest. The human element is the most important part....all other data have a place, but subdued. Individually or together we have no control over quakes, they will occur no matter what. Interest wise, the subject will still be there no matter what also. As amateurs or otherwise, we are helpless to convey any real "help" in that type of situation. For a number of us, all we really do is watch the grams roll in. There is nothing wrong with this, as such; they are really kind of a historical message of an event, generally quite distant from the people really involved. For a number of us, even building a seismograph is quite an undertaking. Its not a simple task. So, when an individual records something, and gets excited by their results, he or she, is really expressing an elation of being able to construct something of their own, and are simply sharing their elation. I would cheer the individuals accomplishment for encouragement and at the same time...wish the bad quakes did not happen. Seismology is a kind of Jeckle & Hide atmosphere! For me that day it was a mixture of feelings. Safely here in Denver, for the most part it was being glued to the chair watching the tv...but at the same time I had to get the old seismo up and running, as it was only sporadic recording. Center the mass, unclog the ink line, put on paper, all the while keeping an ear out for breaking tv changes on the quake. I imagine alot of people where kind of doing the same thing that day, and feeling the same way, if they had a seismo. It seems strange to tell you a survivor of that quake what I felt and what I did that day. I suppose in a vague way, we were sharing the effects, one strongly, one weakly, but both concerned. The most unusal part of this bad quake series for me, was watching an aftershock actually happen on tv from a helicopter, the dust being thrown into the air and the excited newscasters chattering......while I then walked into the graph and watched it coming in...a rerun in a sense. It was strange. It did put on me a stronger feeling of the quake, than if I'd just simply recorded it. So, Walt, thanks for your story..........it was with alot of interest. Meredith Lamb _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: seismo triangulation Date: Tue, 20 Jan 1998 09:56:11 -0800 Sean Thomas et al A thought: I think this would be another future PSN goal: to somehow link (be able to relate) the greater PSN stations together. We would need reasonably accurate time & instrument calibrations (by having a uniform method of performing the