From: Edward Cranswick Subject: Re: Reply (seismology and human consequences) Date: Tue, 30 Sep 1997 15:20:15 -0600 Stephen- I think that your recent correspondence (see excerpt below) about our seismological interest in earthquakes as opposed to their impact on human life has raised some very interesting and important issues that are useful to discuss. I know that when we (the USGS) chase large and damaging earthquakes, e.g., the 1988 Spitak Earthquake in Armenia, our focus on the technical aspects can keep us from being lost in the tragedy, i.e., the death of 1% of the population of Armenia. Alternatively, I remember spending the first few days after the 1994 Northridge Earthquake in California trying to whip our portable autonomous digital seismographs into shape. One afternoon we were on the UC Northridge campus, and if one looked around, one could see some building damage and the traffic lights near the campus that weren't functioning. But then abruptly at 4:00 PM, the lawn sprinklers turned on automatically all around us, but we still couldn't get the damn seismograph to work. In general, I agree with Barry Lotz, "that in the majority of cases that I can think of 'structures kill people not earthquakes'. I consider earthquakes part of the heartbeat of the planet. We have stethoscopes." We make the structures, and we should not forget our responsibility for that. Rather than think that "a good calibration may be bought at the expense of lives and homes", it is much better to think that those people and their dwellings did not die, were not destroyed, in vain, as is often the case. In many cases, the only record of ground motion we have is the damage done or not done to a structure. There were about 150,000 buildings inspected for damage after the Northridge Earthquake, about 20,000 were yellow- and red-tagged (designated as significantly or severely damaged), but the mainshock was locally recorded on scale by only about 200 strong motion accelerometers. So in most cases, in considering why the building on one side of the street collapsed, but the one on the other side did not, we don't know if the building collapsed because of strong ground shaking or because of structural flaws. In my early notion of the PSN, I visualized every house having a combination strong groundmotion accelerometer/ seismograph -- similar to all houses having smoke detectors -- and these cheap, standardized instruments would be calibrated. We need more reliable calibrations. Our old way of calibrating seismographs was with underground nuclear explosions. Prior to the late 1950's, before the US Air Force realized you could detect Soviet nuclear tests with seismographs, seismology was the domain of a handful of international scientists, but then it became Big Business (in terms of scientific funding). That was when calibration became a real important issue, and bombs were the best source of calibration. But if we can't respond to earthquakes which generate much of their energy in the frequency band to which the human nervous system is most sensitive, 1.0-20 Hz, how can we be aware of the really significant threats we face that have much longer time constants, such as global warming and environmental degradation? Barry says we have "stethoscopes" which allow us to hear the small, everyday seismic motions of the Earth above the extraordinary din of cultural noise we create, and this reminds us that She is alive and well. But as Bob Dylan said, "you don't need a weatherman to know which way the wind blows"; Los Angeles has a problem with too little water and gas and too many people; the problem with the place is as much the freeways as the earthquakes, and we are responsible for the former. Earthquakes are a voice that reminds us of our human position in the Cosmos. -Edward Stephen Paul wrote: .... > I am glad that you do think of the result as something other than a blip on > the screen. I live in LA, and when we have a major event here, well, it's > not real pretty. I look at a condemned building every day that was an > apartment bldg. before our last shaker, and I look at it out the window of > my office. There but for the Grace of God went we. And until those > stethoscopes can get people out in time, (which day must surely come, and > that is exactly why these lists have my full support), I do think it is > important to remember that a good calibration may be bought at the expense > of lives and homes. -- 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: Jim Hannon Subject: Re: Reply (seismology and human consequences) Date: Tue, 30 Sep 1997 17:27:17 -0500 Edward Cranswick wrote: > In my early notion of the PSN, I visualized every house having a > combination strong groundmotion accelerometer/ seismograph -- similar to > all houses having smoke detectors -- and these cheap, standardized > instruments would be calibrated. We need more reliable calibrations. There has been a lot of discussion of some sort of instrument to meet these needs. This comment reminds me of an instrument that I heard about years ago. While in school I had a summer job working for a small engineering firm in St. Louis. One of the things they did was to read data from a mechanical strain gage. This device was used to measure the traffic stress on bridges and I think in aircraft structures during flight tests. It was attached to a structural member of the bridge or aircraft and recorded stress as series of scratches on a small polished brass washer. The device was quite small and purely mechanical, it could remain in place for years and record the major flexures of the structural member it was attached to. It seems that such a device could supply at least part of the picture during a major quake. -- Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N 91,39.26W WB0TXL _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: bzimmerman@............ Subject: Image maps Date: Tue, 30 Sep 1997 20:47:17 -0500 (EST) I seem to remember a post from someone offering to produce image maps of quake locations from a table of latitudes and longitudes. Are you still out there? Or does anyone remember the post? Can't seem to find it in the archives. What I'm looking for is the DOS program that does this. It would be nice to be able to easily update my own maps. Brian Zimmerman _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: wb6nvo@............. (Jim Skinner) Subject: Re: Decoding with sound card. Date: Tue, 30 Sep 1997 17:58:29 -0700 (MST) > >I was thinking about making an earthquake alarm using the remote SN. >I plan to use a frequency to voltage converter and set the alarm to >trigger when there is a pre-set voltage difference. Does anyone have any >thoughts on this? If distant enough, it may be used as a warning! > >Thanks, >Peter Fleming >alarm@........... > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > - Peter- I used one (actually several ) for "house alarms" for a number of years... they work great!!! One caution; don't pick one that goes through its autocal routines during the times you would prefer to be sleeping. A cheap and simple way to use one is to make/buy an audio filter and notch out the pilot tone. By varying the selectivity,etc you can actually dial an event of what ever size you want to hear...real easy to set up with an audio sig-gen. Jim Skinner _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: 2.5 event @ Manassas, VA Date: Tue, 30 Sep 1997 21:40:38 -0600 Bob- Very nice record! (reminds me of home: I spent 4 years in graduate school studying East Coast earthquakes). -Edward RLLaney@....... wrote: > > The attached event file is for the subject quake on September 29, 1997. This > is my first submission of an event, so please let me know if additional > information is needed. > > Thank you. > > Bob Laney > > --------------------------------------------------------------- > > Name: 970929B.RL1 > Part 1.2 Type: unspecified type (application/octet-stream) > Encoding: base64 -- 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: Edward Cranswick Subject: Re: More on SG sensor testing. Date: Tue, 30 Sep 1997 22:29:22 -0600 Larry- These are the poles and zeroes of the complex transfer function of the sensor (which I can't help much with) but that does not tell you what the site response transfer function is; or better yet, what the ratio of your site response to that of Berkeley's is. I am still cranking on the file conversion from SDAS (Ted Blank, i.e., PSN) format to DR100 Format with the info you gave me, and this may permit a comparison of site responses. -Edward Larry Cochrane wrote: > > At 09:10 AM 9/24/97 -0400, you wrote: > >Larry, > > I'm reading the e-mail which accumulated during a vacation in Los Alamos > >where my daughter is doing a post-doc in microbiology at the labs. (If you > >want to read some weird stuff, try her web page > >www-ls.lanl.gov/~sbarns/crenarchaeota.html The www-ls is correct but was > >something new to me.) Had a fine time-rode the narrow-gage train from > >Durango to Silverton (CO) again, a trip I can recommend. > > Your daughters research looks very interesting.... > > > I found your shake table work and the subsequent messages very > >interesting. The use of a stepping motor was a slick idea. A few comments > >about your comparison of the SG and Berkeley broadband seismograms:You > >compare them on the basis of peak-to-peak counts. I suggest that the > >comparison would be more meaningful if it was in terms of actual > >velocities, e. g., nanometers/sec. This is what I did in my write-up on > >the meter-movement calibrator for the Lehman. > > The biggest problem with my test was I didn't know how much the table was > moving. Since I was interested in freq. I didn't think it mattered, and, I > don't have the equipment to accurately measure the small movement. > > For the Berkeley seismometer I have the following response information: > > # > # ======== CHANNEL RESPONSE DATA ======== > B050F03 Station: BKS > B050F16 Network: BK > B052F04 Channel: BHN > B052F22 Start date: 1993,348,00:00 > B052F23 End date: No Ending Time > # ======================================= > # + +--------------------------------------------+ > + > # + | Response (Poles & Zeros), BKS ch BHN | > + > # + +--------------------------------------------+ > + > # > B053F03 Transfer function type: A [Laplace Transform > (Rad/sec)] > B053F04 Stage sequence number: 1 > B053F05 Response in units lookup: M/S - Velocity in Meters > Per Second > B053F06 Response out units lookup: V - Volts > B053F07 A0 normalization factor: 987.14 > B053F08 Normalization frequency: 0.02 > B053F09 Number of zeroes: 2 > B053F14 Number of poles: 4 > # Complex zeroes: > # i real imag real_error imag_error > B053F10-13 0 0.000000E+00 0.000000E+00 0.000000E+00 0.000000E+00 > B053F10-13 1 0.000000E+00 0.000000E+00 0.000000E+00 0.000000E+00 > # Complex poles: > # i real imag real_error imag_error > B053F15-18 0 -1.234120E-02 1.234150E-02 0.000000E+00 0.000000E+00 > B053F15-18 1 -1.234120E-02 -1.234150E-02 0.000000E+00 0.000000E+00 > B053F15-18 2 -1.958780E+01 2.456170E+01 0.000000E+00 0.000000E+00 > B053F15-18 3 -1.958780E+01 -2.456170E+01 0.000000E+00 0.000000E+00 > # > # + +-------------------------------------------+ > + > # + | Response (Coefficients), BKS ch BHN | > + > # + +-------------------------------------------+ > + > # > B054F03 Transfer function type: D > B054F04 Stage sequence number: 2 > B054F05 Response in units lookup: V - Volts > B054F06 Response out units lookup: COUNTS - Digital Counts > B054F07 Number of numerators: 51 > B054F10 Number of denominators: 0 > # Numerator coefficients: > # i, coefficient, error > B054F08-09 0 -3.777910E-08 -7.555820E-10 > B054F08-09 1 -4.148830E-07 -8.297660E-09 > B054F08-09 2 9.445450E-06 1.889090E-07 > B054F08-09 3 3.370620E-05 6.741250E-07 > B054F08-09 4 -2.429500E-05 -4.859010E-07 > B054F08-09 5 1.960520E-05 3.921050E-07 > B054F08-09 6 1.544480E-06 3.088960E-08 > B054F08-09 7 -2.150600E-05 -4.301210E-07 > B054F08-09 8 2.705530E-05 5.411070E-07 > B054F08-09 9 -1.676900E-05 -3.353810E-07 > B054F08-09 10 5.124170E-03 1.024830E-04 > B054F08-09 11 1.779800E-03 3.559600E-05 > B054F08-09 12 -4.332210E-03 -8.664430E-05 > B054F08-09 13 7.430310E-03 1.486060E-04 > B054F08-09 14 -1.039340E-02 -2.078670E-04 > B054F08-09 15 1.183280E-02 2.366560E-04 > B054F08-09 16 -1.055880E-02 -2.111760E-04 > B054F08-09 17 6.859030E-03 1.371810E-04 > B054F08-09 18 1.163370E-02 2.326740E-04 > B054F08-09 19 -2.604490E-02 -5.208970E-04 > B054F08-09 20 4.648550E-02 9.297090E-04 > B054F08-09 21 -7.015840E-02 -1.403170E-03 > B054F08-09 22 9.522160E-02 1.904430E-03 > B054F08-09 23 -1.275080E-01 -2.550170E-03 > B054F08-09 24 1.436970E-01 2.873940E-03 > B054F08-09 25 8.778300E-01 1.755660E-02 > B054F08-09 26 8.819290E-02 1.763860E-03 > B054F08-09 27 -1.059150E-01 -2.118300E-03 > B054F08-09 28 8.731180E-02 1.746240E-03 > B054F08-09 29 -6.899650E-02 -1.379930E-03 > B054F08-09 30 4.899210E-02 9.798410E-04 > B054F08-09 31 -3.020580E-02 -6.041160E-04 > B054F08-09 32 1.640370E-02 3.280730E-04 > B054F08-09 33 2.733980E-03 5.467960E-05 > B054F08-09 34 -7.899160E-03 -1.579830E-04 > B054F08-09 35 1.036420E-02 2.072840E-04 > B054F08-09 36 -9.902790E-03 -1.980560E-04 > B054F08-09 37 7.607170E-03 1.521430E-04 > B054F08-09 38 -4.881500E-03 -9.763010E-05 > B054F08-09 39 2.557260E-03 5.114520E-05 > B054F08-09 40 4.751230E-03 9.502450E-05 > B054F08-09 41 -8.744070E-05 -1.748810E-06 > B054F08-09 42 3.545030E-05 7.090060E-07 > B054F08-09 43 -3.244920E-05 -6.489850E-07 > B054F08-09 44 9.078710E-06 1.815740E-07 > B054F08-09 45 1.395880E-05 2.791750E-07 > B054F08-09 46 -2.044260E-05 -4.088520E-07 > B054F08-09 47 3.442010E-05 6.884020E-07 > B054F08-09 48 7.743230E-06 1.548650E-07 > B054F08-09 49 -3.925280E-07 -7.850560E-09 > B054F08-09 50 -2.914360E-08 -5.828710E-10 > # > # + +---------------------------------------+ > + > # + | Channel Sensitivity, BKS ch BHN | > + > # + +---------------------------------------+ > + > # > B058F03 Stage sequence number: 0 > B058F04 Sensitivity: 1.047200E+09 > B058F05 Frequency of sensitivity: 2.000000E-02 HZ > B058F06 Number of calibrations: 0 > # > > Unfortunately I have no idea on how to read this... If someone does, please > let me know. > > -Larry > > _____________________________________________________________________ > > 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: dean sevold Subject: Sound cards Date: Tue, 30 Sep 97 14:24:42 PDT All: Soundblaster has a large file for use with the SB boards; its the Sound = Blaster Dos Developers Kit,and includes drivers in most programming langu= ages. Soundblaster can be reached at http://www.creaf.com . _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Date: Tue, 30 Sep 1997 10:10:48 -0700 From: Norman Davis WB6SHI Subject: Re: Decoding with sound card. Date: Tue, 30 Sep 1997 19:57:05 >>I was thinking about making an earthquake alarm using the remote SN. >>I plan to use a frequency to voltage converter and set the alarm to >>trigger when there is a pre-set voltage difference. Does anyone have any >>thoughts on this? If distant enough, it may be used as a warning! I did too. I had a pll tuned to the pilot tone and when it changed freq I had it open a speaker so I could hear the tone. It worked great but drove the wife nuts cuz we had some RFI that would hit it some times and when the pilot tone droped the squelch would open and set the thing off. Norman Davis WB6SHI Email normd@............. Shingle Springs, Ca, USA it ain't local... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: Image maps Date: Thu, 2 Oct 1997 09:44:07 -0400 Brian Zimmerman, Yes, I did (and still do) offer to make a world map of your 'quakes if you supply a list of lats & lons. I use a rather involved process using a CAD (computer aided design) progr= am called DesignCAD. This is about $300. It included a BASIC-like programming language which = I use to read data files and plot points. If you have something like this,= I can supply the x-y pairs which draw the map and you can plot your own 'quakes. If you want to send me your 'quakes, make an ASCII file of lats & lons separated by a comma with one lat-lon pair per line. Include only lats &= lons, not magnitudes or other stuff. Bob Barns = _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: Re: Image maps Date: Fri, 03 Oct 1997 01:57:46 +1200 Bob, brian was looking for a way to plot the quakes on a relief map basically the same as I used for the PSN world map I supplied him with the map earlier in the week it would be great if there was a prog available that any map could be loaded into and then have the data plotted onto it Dave At 09:44 AM 10/2/97 -0400, you wrote: >Brian Zimmerman, > Yes, I did (and still do) offer to make a world map of your 'quakes if >you supply a list of lats & lons. >I use a rather involved process using a CAD (computer aided design) program >called DesignCAD. >This is about $300. It included a BASIC-like programming language which I >use to read data files and plot points. If you have something like this, I >can supply the x-y pairs which draw the map and you can plot your own >'quakes. > If you want to send me your 'quakes, make an ASCII file of lats & lons >separated by a comma with one lat-lon pair per line. Include only lats & >lons, not magnitudes or other stuff. >Bob Barns > > > > >_____________________________________________________________________ > >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 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: Don Rose Subject: Re: Image maps Date: Thu, 02 Oct 1997 09:03:37 -0700 Robert L Barns wrote: > > Brian Zimmerman, > Yes, I did (and still do) offer to make a world map of your 'quakes if > you supply a list of lats & lons. > I use a rather involved process using a CAD (computer aided design) program > called DesignCAD. > This is about $300. It included a BASIC-like programming language which I > use to read data files and plot points. If you have something like this, I > can supply the x-y pairs which draw the map and you can plot your own > 'quakes. > If you want to send me your 'quakes, make an ASCII file of lats & lons > separated by a comma with one lat-lon pair per line. Include only lats & > lons, not magnitudes or other stuff. > Bob Barns > > > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L please delete me from the list. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: GeE777@....... Subject: Re: Image maps Date: Thu, 2 Oct 1997 14:14:52 -0400 (EDT) Have you looked into -- DeLorme Mapping Lower Main Street, P.O.Box 298 Freeport, ME 04032 USA Telephone (207)865-1234 It comes on a CD Rom George << n a message dated 97-10-02 10:03:41 EDT, you write: Bob, brian was looking for a way to plot the quakes on a relief map basically the same as I used for the PSN world map I supplied him with the map earlier in the week it would be great if there was a prog available that any map could be loaded into and then have the data plotted onto it Dave >> _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Trigger alogorithm Date: Thu, 02 Oct 1997 13:56:31 -0600 Barry- I couldn't follow the your frequency domain detection (trigger) algorithm in detail without having to think, which is a problem for me, but I am wondering why you triggering in realtime rather than recording continuously and then detecting by post processing and/or by correlation with a catalog of events from CalNet, NEIC, etc. -Edward barry lotz wrote: > > To All > I have been trying for a while to develope a "better" event triggering > routine for my system. The hope is to be able to detect teleseismic and > small local events in a noisy environment. I currently work in a trigger > environment rather than a continuous recording one. I'll try to describe > what I've been up to. > My detection routine is based on that described by Goforth & Herrin in > BSSA vol 71,no 4 , Aug 1981."An Automatic Seismic Signal Detection Algorithm > Based on the Walsh Transform". The basic description of the routine is as > follows. A window of data is acquired (in my system, 512 readings). A > transform is performed to convert this data to the frequency domain. G & H > used a Walsh transform for speed ,at a time when processors were slower. I > tried The Walsh routine and it definitely was faster but it produces aliases. > I use a 512 point FFT. The individual frequency magnitudes of the spectrum > are then summed. If one does not want to include a particular frequency it > can be avoided in the summing process. This weighted sum is stored as the > newest entry in a 512 point sequence of sums. The oldest sum is also > deleted at this time. The 512 entries are then sorted by size and the 75th % > sum is compared to the 50th % sum. A trigger threshold is obtained from the > following equation: Threshold = median + K*( 75% - median). K is a constant > which is in the range of 3-5. The current sum is then compared with this > continously varing threshold. If the current sum exceeds the threshold an > event is triggered. If the sum does not exceed the threshold it is saved and > another 512 points of data are acquired and the process is repeated.Actually > the window is 480 points of new data, I used an overlapping window of 32 > points. Because of transients, I wait to have 7-8 sums in sequence before I > trigger an event. I continue to save data, once the trigger is initiated, > until the FFT sum falls below the threshold. I then save the event to a > file. Because of lost P & S waves I keep two revolving 2k to 4k buffers > which are saved in front of the first trigger point( like Ted Blank's EMON). > I currently run the system at 8 hz just for teleseismic events. It has > helped me to detect events which I couldn't possibly have done before ,ie. > I can crank the gain up quite a bit. The only real problem I have had to > date has been with wind and trees. Wind gusts are transient noise in the > frequency range I am interested in. They don't trigger an event due to their > short duration but over time they raise the threshold so high that real > events can slip by. This winter will help the learning curve. I'll keep you > posted. I hope I haven't been to confusing. > > PS > > I have a FIR digital filter in the routine and have used it with limited > success. I can't get IIR filters to be stable over time. > > _____________________________________________________________________ > > 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: Jim Hannon Subject: Re: Decoding Date: Thu, 02 Oct 1997 17:15:44 -0500 Phil Giannini wrote: > > My > question is, does anybody know if there is a way to take a PSN file recorded > on SDR and turn it into a file that can be read by a sound card in the same > manner as the Landers quake was. > This question got me going. I have also wanted to listen to quakes. I did a little web browsing and found a shareware program Cool Edit 96 http://www.syntrillium.com/load.htm for those who use Win95 or NT this program will let you listen to files in PSN event file format. Since except for the header the data in the file is recorded as 16 bit PCM. Just ask Cool Edit to open "all files" and tell it 16 bit mono PCM and pick a sampling rate that sounds good. You will have to ignore or edit off the header data at the beginning of the file. You can then save the file in .au, .wav or your choice of audio formats. I converted one of Larry's files and put it on my web page at http://soli.inav.net/~jmhannon/seismology.html Click on Listen to an Earthquake. I started writing a File filter for Col Edit that would read PSN files and remove the header info but there is a small problem with the use of using the file extension to identify stations and Microsoft's use of extension to identify file types. Cool Edit only lets you put 4 different file extensions in a filter. So you would have to rename files to one of the extensions in the filter for it to work. -- Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N 91,39.26W WB0TXL _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Stephen Caruso Subject: Re: Image maps Date: Thu, 2 Oct 1997 20:29:23 -0400 (EDT) If you have windows 95 you can download software called imaging from microsoft imaging and edit faxes and images... so then download a map and edit it! STEPHEN CARUSO CET KB8UGH _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: Trigger alogorithm Date: Thu, 02 Oct 1997 09:20:47 -0700 Edward I guess because it's a challange. I thinks it also gives me a better understanding of how the event is composed. It also would be useful to me in a remote, "quiet" site with limited memory capacity. I don't know... maybe also because it's there. :-} Barry Edward Cranswick wrote: > > Barry- > I couldn't follow the your frequency domain detection (trigger) > algorithm in detail without having to think, which is a problem for me, > but I am wondering why you triggering in realtime rather than recording > continuously and then detecting by post processing and/or by correlation > with a catalog of events from CalNet, NEIC, etc. > -Edward > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Stephen Caruso Subject: Manassas quake? Area history? Date: Fri, 3 Oct 1997 21:44:09 -0400 (EDT) I was told there was an earthquake in VA recently. Did anybody see this one? It was 2.5. Does Va get many ever? STEPHEN CARUSO CET KB8UGH _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Stephen Caruso Subject: Re: Manassas quake? Area history? Date: Fri, 3 Oct 1997 21:48:23 -0400 (EDT) 1:30 est 17:30 uct STEPHEN CARUSO CET KB8UGH _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: George Bush Subject: Wow, what was that Date: Sat, 04 Oct 1997 08:36:20 -0700 Did anyone else detect a large event at about 11:00 UT 10/4/97? My digitizing system is off-line, but the drum recorder pen went stop-to-stop. The event lasted about 15 minutes, so was not nearby, but also was probably not on the other side of the world. I really miss being able to use winquake to tell how far away the event was. George Bush Sea Ranch, CA 38.74, -123.5 _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Marnie Gannon Subject: Re: Wow, what was that Date: Sat, 04 Oct 1997 09:52:00 -0700 George Bush wrote: > > Did anyone else detect a large event at about 11:00 UT 10/4/97? My > digitizing system is off-line, but the drum recorder pen went stop-to-stop. > The event lasted about 15 minutes, so was not nearby, but also was probably > not on the other side of the world. > > I really miss being able to use winquake to tell how far away the event was. > > George Bush > Sea Ranch, CA > 38.74, -123.5 > e0725c0-s- r n USGS-EARTHQUAKE-REPORT 10-04 0313 EARTHQUAKE REPORT == PRELIMINARY EARTHQUAKE REPORT == Rapid Earthquake Location Service U.S. Geological Survey, Menlo Park, California U.C. Berkeley Seismographic Stations, Berkeley, California Version 2: Updates lower and earlier versions of this earthquake report This event has been reviewed by David Oppenheimer-USGS A MODERATE EARTHQUAKE OCCURRED AT 03:57 AM PDT Saturday, Oct 04, 1997. THE MAGNITUDE 5.1 (ML) EVENT IS LOCATED 67 MILES W OF TRINIDAD, CA THE HYPOCENTRAL DEPTH IS 4.9 MILES. N.B. This earthquake occurs outside our network. The location is probably uncertain by 10 km and the depth is currently indeterminate. PRINCIPAL EARTHQUAKE PARAMETERS _______________________________ Magnitude : 5.12 ML Event Date & Time : 10/04/1997 03:57:33 AM PDT 10/04/1997 10:57:33 UTC Location : 41.0448 N, 125.4258 W : (41 deg. 2.69 min. N, 125 deg. 25.55 min. W) Depth : 7.9 km. deep ( 4.9 miles) Location Quality : Poor 108 km ( 67 miles) W (270 degrees) of Trinidad, CA 109 km ( 68 miles) WNW (285 degrees) of Eureka, CA 111 km ( 69 miles) WNW (298 degrees) of Ferndale, CA 112 km ( 69 miles) W (276 degrees) of McKinleyville, CA 115 km ( 71 miles) W (280 degrees) of Arcata, CA ADDITIONAL EARTHQUAKE PARAMETERS ________________________________ number of phases : 215 rms misfit : 0.39 seconds horizontal location error : 1.6 km vertical location error : 33.1 km maximum azimuthal gap : 236 degrees distance to nearest station : 112. km In region 2 (070) PACIFIC OCEAN event ID: 1020477 ====================================================================== ==== U.S. Geological Survey | Seismographic Station Seismology Section | 475 McCone Hall 345 Middlefield Road - MS 977 | U.C. Berkeley Menlo Park, CA 94025 | Berkeley, CA 94720- 4760 Voice : 415-329-4085 | 510-642-3977 Earthquake Info : 415-329-4025 | 510-642-2160 Fax : 415-329-5163 | 510-643-5811 E-mail : ncsn@................... | bdsn@................ edu More Information about this event and other earthquakes is available on the Worldwide Web at http://quake.wr.usgs.gov EDIS-10-04-97 0426 PDT _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: lahr@................. (Dr. John Lahr (USGS-GI Seismologist)) Subject: Re: Image maps Date: Sat, 4 Oct 1997 11:33:48 -0800 There is a program available on the web called Seismic that can plot earthquake epicenters on a map, in cross section, or in 3-D view. It actually plots them one at a time in speeded up time so that you see the pattern of seismicity as it develops over time. The program comes with a global data set and shaded relief background maps for the entire world and for many sub-regions of the world. It also includes a program that can convert from various formats into the ".hy3" format used for its earthquake data sets. There are far too many features to describe in detail here. For more information on Seismic, check out Alan Jones' home page at: http://sunquakes.geol.binghamton.edu/faculty/jones/ The current version of the program is called Seismic/Eruption, as it also displays volcanic eruptions as they occur. This program, and another called Seismic/Waves are included in a new exhibit at the Smithsonian in Washington. Seismic/Waves is a neat program that shows seismic wave fronts as they move outward from an earthquake's hypocenter. These are shown graphically on a cross section of the earth, so one can see how the structure of the earth produces reflection, refractions, and shadow zones. On the top of the screen, one sees an actual seismic record with the phases identified. The programs are free, but a $30 registration fee is requested if you enjoy using them. For teachers and students in K-12, registration is not requested. JCLahr ################################## John C. Lahr ################################# Seismologist ################################ U.S. Geological Survey ############################### c/o Geophysical Institute ############################## 903 Koyukuk Drive ~~~~~~~~~~~~~~ Get ~~~~~~~~~~ ############################# ########################################################### P.O. Box 757320 ################################ Fairbanks, AK 99775 ################################# Phone: (907) 474-7997 ################################## Fax: (907) 474-5618 ~~~~~~~~ the thrust? ~~~~~~~~~~~~~~ lahr@........ #################################### http://www.aeic.alaska.edu/Input/lahr/ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: new event Date: Sat, 04 Oct 1997 06:53:13 -0700 All Looks like something coming thru @ 01:37 UTC 10/05. Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: Re: new event Date: Sun, 05 Oct 1997 14:22:32 +1200 how's it look barry, was it an aftershk to the offshore cal. 5.1 ?? Dave At 06:53 AM 10/4/97 -0700, you wrote: >All > Looks like something coming thru @ 01:37 UTC 10/05. > Barry > >_____________________________________________________________________ > >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: barry lotz Subject: Re: new event Date: Sat, 04 Oct 1997 07:57:39 -0700 David Weird. Maybe it's my washing machine. :-]. I'll upload it. Barry David A Nelson wrote: > > how's it look barry, was it an aftershk to the offshore cal. 5.1 ?? > > Dave > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: Re: new event Date: Sun, 05 Oct 1997 15:07:32 +1200 well barry, never seen anything like that before the mind boggles !!! Dave At 07:57 AM 10/4/97 -0700, you wrote: >David > Weird. Maybe it's my washing machine. :-]. I'll upload it. > Barry > >David A Nelson wrote: >> >> how's it look barry, was it an aftershk to the offshore cal. 5.1 ?? >> >> 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: "Dott. Roberto E. Pozzo" Subject: PSN Italy works ! Date: Sun, 05 Oct 1997 13:03:57 +0200 Dear Larry C.,Edward C. and all PSN guys . PSN ITALY is now a reality ! Few days ago, as you know, in Central Italy two earthquakes (5.5 and 5.9 followed by more than 90 aftershocks) have caused 6 victims, about 120 injuried and more of 5000 homeless).The famous S. Francesco Church in Assisi also has suffered very serious damages ( a part of a Cimabue's masterpiece is forever lost ) . Francesco,Giovanni and I are keeping in touch H24 by phone and we exchange our wq recordings daily for study proposals. This in the spirit of P.S.N. and the first really well-working collaboration between amateurs in seismology in Italy during a seismic period. Count on us ! roberto _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: mark widerstrom Subject: Re: Cost for seismograph Date: Sun, 05 Oct 1997 07:04:30 -0500 Anyone have the costs involved with doing a seismograph? I see alot of portable units but something not pocket eating would be appreciated. I am a ham radio operator and im looking at frequencies above 16 mhz that could be reading seismo triggers. Thanks for your time Markww in Houston Texas N5UOA Support your local disabled veterans units. Anyone have the costs involved with doing a seismograph?  I see alot of portable units but something not pocket eating would be appreciated.  I am a ham radio operator and im looking at frequencies above 16 mhz that could be reading seismo triggers.  Thanks for your time

Markww  in Houston Texas
N5UOA

Support your local disabled veterans units. From: Larry Cochrane Subject: Re: Manassas quake? Area history? Date: Sun, 05 Oct 1997 11:34:21 -0700 At 09:44 PM 10/3/97 -0400, Stephen Caruso wrote: I don't know about the history part, but, Bob Laney who lives in Herndon VA, about 15 to 25 miles from the event, received this event and it was his first one! He just got his system up and running when he capture the event. He sent in a very nice seismogram that can be download using the following URL: ftp:://psn.quake/net/quakes/9709/970929a.rl1. Bob Laney, can you send Dave Nelson your station info so he can add it to the PSN Map? Thanks, and good job getting your station up and running! -Larry Cochrane Redwood City, PSN >I was told there was an earthquake in VA recently. Did anybody see this >one? It was 2.5. Does Va get many ever? > >STEPHEN CARUSO CET >KB8UGH > > > >_____________________________________________________________________ > >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: Larry Cochrane Subject: Re: PSN Italy works ! Date: Sun, 05 Oct 1997 11:50:08 -0700 Hi Guys, Great! Can you also send your event files to event@............. for archiving? This way we call can see them... I would also like to remind people that I have the new NewFile mailing list that will send you a email message when people send in event files to the event@... address above. This email message will not have the attached file like the NewEvent mailing list. You can use the web page at http://psn.quake.net/maillist.html to subscribe/unsubscribe to all of the lists I have. -Larry Cochrane Redwood City, PSN At 01:03 PM 10/5/97 +0200, you wrote: >Dear Larry C.,Edward C. and all PSN guys . > >PSN ITALY is now a reality ! Few days ago, as you know, in Central Italy >two earthquakes (5.5 and 5.9 followed by more than 90 aftershocks) have >caused 6 victims, about 120 injuried and more of 5000 homeless).The >famous S. Francesco Church in Assisi also has suffered very serious >damages ( a part of a Cimabue's masterpiece is forever lost ) . > >Francesco,Giovanni and I are keeping in touch H24 by phone and we >exchange our wq recordings daily for study proposals. > >This in the spirit of P.S.N. and the first really well-working >collaboration between amateurs in seismology in Italy during a seismic >period. > >Count on us ! > roberto > > >_____________________________________________________________________ > >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: Larry Cochrane Subject: Re: Cost for seismograph Date: Sun, 05 Oct 1997 12:18:29 -0700 At 07:04 AM 10/5/97 -0500, Mark wrote: > Anyone have the costs involved with doing a seismograph? That's a hard one... depends on what type of sensor you want to make (Lehman, SG, or something else), parts and equipment you have on hand, etc etc etc. Besides the sensor you will need some type of recording device. This could be a chart recorder (arrgggg) or a computer system with an Analog to Digital convert card and software. The homebuilt FAQ at http://psn.quake.net/info/homefaq.txt has more info about the hardware/software need to get a station up and running. >>> I see alot of portable units but something not pocket eating would be appreciated. I am a ham radio operator and im looking at frequencies above 16 mhz that could be reading seismo triggers. Thanks for your time Markww in Houston Texas <<<<<<<< Not sure what portable units you are talking about? As far as "looking for seismic triggers above 16 mhz", you on your own on that one... If you make a seismometer, you will be picking up seismic waves in the 30 second to 20hz range. Hope this helps. -Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: Re: Cost for seismograph Date: Mon, 06 Oct 1997 10:57:22 +1200 Larry, at least when my HDD died 3 days ago the good ol' pen recorder still chugged relentlessly on Dave Larry wrote: This could be a chart recorder (arrgggg) or a computer system with an Analog to Digital convert card and software. 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: PSN Italy works ! Date: Sun, 05 Oct 1997 23:10:10 -0600 Roberto- I am sorry to hear about the deaths, injuries and damage caused by the earthquake. I am glad to hear that your PSN connection has helped you, Giovanni, and Francesco to experience what has happened together ... and so you are closer to each other and to the earth of Italy. -Edward Dott. Roberto E. Pozzo wrote: > > Dear Larry C.,Edward C. and all PSN guys . > > PSN ITALY is now a reality ! Few days ago, as you know, in Central Italy > two earthquakes (5.5 and 5.9 followed by more than 90 aftershocks) have > caused 6 victims, about 120 injuried and more of 5000 homeless).The > famous S. Francesco Church in Assisi also has suffered very serious > damages ( a part of a Cimabue's masterpiece is forever lost ) . > > Francesco,Giovanni and I are keeping in touch H24 by phone and we > exchange our wq recordings daily for study proposals. > > This in the spirit of P.S.N. and the first really well-working > collaboration between amateurs in seismology in Italy during a seismic > period. > > Count on us ! > roberto > > _____________________________________________________________________ > > 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: Edward Cranswick Subject: [Fwd: Manassas quake] Date: Sun, 05 Oct 1997 23:14:29 -0600 -- 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". From: Kees Verbeek Subject: Quake!!! Date: Tue, 7 Oct 1997 02:31:56 +0200 (MET DST) Hi all, Just had a quake , start , about 23.30 i'm afraid its Itali again?!!! Greetings , Kees Verbeek Holland. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Francesco" Subject: R: Quake!!! Date: Tue, 7 Oct 1997 02:40:42 +0100 Hello Kees, yes. Another medium quake, perhaps 5.5 Ms Have you registered the event? Please, get me file as soon as possible. I leave 40 km far the epicentre. Thank you Francesco Nucera ---------- > Da: Kees Verbeek > A: PSN-L Mailing List > Oggetto: Quake!!! > Data: marted=EC 7 ottobre 1997 1.31 > = > Hi all, > = > = > = > Just had a quake , start , about 23.30 i'm afraid its Itali again?!!! > = > Greetings , > = > = > Kees Verbeek > Holland. > = > = > _____________________________________________________________________ > = > 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: "Dott. Roberto E. Pozzo" Subject: Re: Quake!!! Date: Tue, 07 Oct 1997 02:45:04 +0200 Kees Verbeek wrote: > > Hi all, > > Just had a quake , start , about 23.30 i'm afraid its Itali again?!!! > > Greetings , > > Kees Verbeek > Holland. > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L Yes, Kes it's a Central Italy quake . Again ! provisional calculations reports M +- 5.5 . Epicentral zone: near Assisi . Mercalli VII/VIII. No new victims reported (by now ) roberto _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Kees Verbeek Subject: Re: R: Quake!!! Date: Tue, 7 Oct 1997 03:41:49 +0200 (MET DST) At 02:40 7-10-97 +0100, you wrote: >Hello Kees, >yes. Another medium quake, perhaps 5.5 Ms >Have you registered the event? > >Please, get me file as soon as possible. > >I leave 40 km far the epicentre. > >Thank you > >Francesco Nucera > >---------- Hello Francesco, 40 km. !!!!!!!! I hope everything is alright over there. Sorry I can't give any computer-file about the quake because i'm a kind of old-fashion seismo-fanatic . I only record on a home-brewed drum recorder,that's behind me now , so I immediately can see when something goes wrong. Perhaps France can? again sorry for no help, greetings, Kees Verbeek Holland _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Needs for informations about a vertical sensor sismograph Date: Mon, 06 Oct 1997 18:02:01 -0700 Hi, I received this yesterday. Can anyone help them? They are not on the PSN-L list so please send email directly to them and CC the list. Thanks, -Larry Cochrane Redwood City, PSN >X-Authentication-Warning: www.utbm.fr: news set sender to using -f >Date: Sat, 05 Oct 1996 14:56:18 +0100 >From: Yohann LEDIEU >X-Mailer: Mozilla 3.01 (WinNT; I) >To: cochrane@.............. >CC: nicolas-rivron@....... >Subject: Needs for informations about a vertical sensor sismograph >X-MIME-Autoconverted: from 8bit to quoted-printable by www.utbm.fr id OAA02937 > >Dear sir >We are two french students from the Institut polytechnique de Sevenans >(IPSé). >As a project, this year, we have to build a vertical sensor sismograph >so that we need some more informations about it. >We already read your web site but we didn't found anything about >vertical sensor. >Could you please help us by sending us informations, plans or web >addresses. > yours faithfully, > > Rivron Nicolas > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: [Fwd: USGS Menlo Park move] Date: Mon, 06 Oct 1997 23:26:12 -0600 -- 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". From: Edward Cranswick Subject: Re: USGS Menlo Park move Date: Mon, 06 Oct 1997 23:37:46 -0600 Ted Blank- But the reality of the situation is that you now, and the original PSN members then, and the USGS Menlo Park all live where the earthquakes are .... but I just live in Colorado and talk about it. So ultimately it's up to all you Bay Area people to be aware of and prepare yourself for the earthquakes that are part of what makes the Bay Area such a beautiful place to live. However, thank you for letting me know what's happening. -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: Needs for informations about a vertical sensor sismograph Date: Mon, 06 Oct 1997 23:40:25 -0700 Larry Cochrane wrote: >=20 > Hi, >=20 > I received this yesterday. Can anyone help them? They are not on the PS= N-L > list so please send email directly to them and CC the list. >=20 > Thanks, >=20 > -Larry Cochrane > Redwood City, PSN >=20 > >X-Authentication-Warning: www.utbm.fr: news set sender to > using -f > >Date: Sat, 05 Oct 1996 14:56:18 +0100 > >From: Yohann LEDIEU > >X-Mailer: Mozilla 3.01 (WinNT; I) > >To: cochrane@.............. > >CC: nicolas-rivron@............. I sent them the Vertical.GIF and AMP_= 2.GIF files file from the San Jose BBS. Regards, Steve Hammond PSN - San Jose, California=20 > >Subject: Needs for informations about a vertical sensor sismograph > >X-MIME-Autoconverted: from 8bit to quoted-printable by www.utbm.fr id > OAA02937 > > > >Dear sir > >We are two french students from the Institut polytechnique de Sevenans > >(IPS=E9). > >As a project, this year, we have to build a vertical sensor sismograph > >so that we need some more informations about it. > >We already read your web site but we didn't found anything about > >vertical sensor. > >Could you please help us by sending us informations, plans or web > >addresses. > > yours faithfully, > > > > > > >=20 > _____________________________________________________________________ >=20 > Public Seismic Network Mailing List (PSN-L) >=20 > To leave this list email listserver@............. with the body of the > message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: shammon1@............. Subject: Re: Needs for informations about a vertical sensor sismograph Date: Mon, 06 Oct 1997 23:57:11 -0700 Larry, I sent the two students the Vertical.GIF file and AMP_2.GIF file from the PSN San Jose BBS.=20 Regards, Steve Hammond PSN San Jose, California Larry Cochrane wrote: >=20 > Hi, >=20 > I received this yesterday. Can anyone help them? They are not on the PS= N-L > list so please send email directly to them and CC the list. >=20 > Thanks, >=20 > -Larry Cochrane > Redwood City, PSN >=20 > >X-Authentication-Warning: www.utbm.fr: news set sender to > using -f > >Date: Sat, 05 Oct 1996 14:56:18 +0100 > >From: Yohann LEDIEU > >X-Mailer: Mozilla 3.01 (WinNT; I) > >To: cochrane@.............. > >CC: nicolas-rivron@....... > >Subject: Needs for informations about a vertical sensor sismograph > >X-MIME-Autoconverted: from 8bit to quoted-printable by www.utbm.fr id > OAA02937 > > > >Dear sir > >We are two french students from the Institut polytechnique de Sevenans > >(IPS=E9). > >As a project, this year, we have to build a vertical sensor sismograph > >so that we need some more informations about it. > >We already read your web site but we didn't found anything about > >vertical sensor. > >Could you please help us by sending us informations, plans or web > >addresses. > > yours faithfully, > > > > > > >=20 > _____________________________________________________________________ >=20 > Public Seismic Network Mailing List (PSN-L) >=20 > 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: lighter side of software Date: Wed, 08 Oct 1997 12:58:55 +1200 hi all, here's a little gem I discovered that I hope will bring a smile to the faces of the masses DEFINITION OF WINDOWS 95: 32-bit extensions and a graphical shell for a 16-bit patch to an 8-bit operating system originally coded for a 4-bit microprocessor, written by a 2-bit company that can't stand 1-bit of competition. 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: lighter side of software Date: Wed, 08 Oct 1997 11:41:09 -0700 Very good... and unfortunately true! -Larry At 12:58 PM 10/8/97 +1200, you wrote: >hi all, > here's a little gem I discovered that I hope will bring a smile to >the faces of the masses > > DEFINITION OF WINDOWS 95: > > 32-bit extensions and a graphical shell for a > 16-bit patch to an > 8-bit operating system originally coded for a > 4-bit microprocessor, written by a > 2-bit company that can't stand > 1-bit of competition. > > >Dave _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: lighter side of software Date: Wed, 08 Oct 1997 14:19:49 -0600 Dave & Larry- But that proves the system and the people who use it are very adaptable unlike some other systems which required an investment of a 100k just to logon on -- and that is the sign of a organism/system that survives by evolving. -Edward Larry Cochrane wrote: > > Very good... and unfortunately true! > -Larry > > At 12:58 PM 10/8/97 +1200, you wrote: > >hi all, > > here's a little gem I discovered that I hope will bring a smile to > >the faces of the masses > > > > DEFINITION OF WINDOWS 95: > > > > 32-bit extensions and a graphical shell for a > > 16-bit patch to an > > 8-bit operating system originally coded for a > > 4-bit microprocessor, written by a > > 2-bit company that can't stand > > 1-bit of competition. > > > > > >Dave > > _____________________________________________________________________ > > 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: Robert L Barns <75612.2635@..............> Subject: compare. of 3 sensors for Kermadec Date: Wed, 8 Oct 1997 20:28:12 -0400 Larry, I downloaded 970920A.BKN, .LC1 & .LC3. of the Kermadec 6.9 event. = Thanks for taking the trouble of making files so that it is easy to compa= re them. The comparison is very informative. (My great bad luck was to have= my rig down for this event--we had a power dip while I was out of town an= d I had not provided for auto restart of SDR in AUTOEXEC.BAT.) sensor p-p surf p-p bg = S N = S/N .BKN Berk. broadband 5340 200 27 .LC1 Lehman 3440 170 20 .LC3 S-G new integ. 9740 800 12 Since the p-p bg is an eyeball est., I'm not sure that the difference between 27 and 20 is significant. Since the S/N ratio would be dependent= on the high freq. cutoff, I looked at the FFT for all three and it looks like they are all the same. The visual appearance of all three 'grams is remarkably similar. Lay = & Wallace ("Modern Global Seismology") p 188 show that the broadband sensor= s have response from ~ 9 Hz to less than .001 Hz. I was amazed that the FFT's for the three sensors were remarkably similar and esp. that they showed about the same fraction of energy at low freqs., say below .02 Hz.= Since I have only a Lehman, I was delighted to see that yours was only slightly inferior to the broadband rig. I suppose that the Berk. sensor = is in a good location (borehole?) so the similarity of the S/N must make you= feel good about your location. I have some questions:1. Since the S wave is very strong, how come the = SS and SSS seem to be absent? 2. The LQ calculates to be at about 16:56:12= =2E = What is the nice 'blob' (do you have a better term for this?) centered a= t about 16:51:48? This 'blob' has a period of about 23" and the sections around the LQ and LR are about 16". I would greatly appreciate your repeating this exercise the next time w= e have a teleseismic boomer--one which I should also get. A suggestion for a new feature for WINQUAKE--how about a facility for getting an RMS avg. value for a zoomed region? This would be a better meas. of the background amplitude. Maybe you can think of something bett= er than RMS. Bob Barns = = = = _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Kasey Benson" Subject: Re: Wow, what was that Date: Wed, 8 Oct 1997 20:03:14 -0700 ---------- > How does one get off this list. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: frankcnd@.......... (Frank Condon) Subject: Date: Thu, 9 Oct 1997 02:24:49 -0700 (PDT) Subject: Parkfield Prediction X-Mailer: Hi all! I remember reading about the possibility of an 8.0 occurring on the San Andreas fault immediately following a 6.0 or greater in the Parkfield area. Can anyone enlighten me about this theory? Also, seeing very erratic low frequency 0-3 Hz geo-magnetic field disturbances in the Cucamonga/San Bernardino County area on my equipment. Can anyone else correlate with me on this? I think it might be something else going on on the San Jacinto fault that is causing it. reply to: frankcnd@.......... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Stephen Paul Subject: Re: lighter side of software Date: Thu, 09 Oct 1997 02:36:20 -0700 David A Nelson wrote: > hi all, > here's a little gem I discovered that I hope will bring a smile to > the faces of the masses > > DEFINITION OF WINDOWS 95: > > 32-bit extensions and a graphical shell for a > 16-bit patch to an > 8-bit operating system originally coded for a > 4-bit microprocessor, written by a > 2-bit company that can't stand > 1-bit of competition. > > 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 > > ____________________________________________________________________ That one kept me laughing for hours, Dave! Thanks for passing it along. -- Stephen :^) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: GeoMonitr@....... Subject: Re: HAM interested in earthquake prediction Date: Thu, 9 Oct 1997 12:25:12 -0400 (EDT) Many people have been trying to duplicate the experiments of Anthony Fraser-Smith at Stanford, by detecting ULF signals that may be a link between earthquake precursors and human reactions. I started a newsletter on the subject, GeoMonitor, and I have all 6 years of back issues, including some amateur circuits for ULF detection. The newsletter is now being published by Charles Patton, 21490 Camino Arriba, Murrieta, CA 92562; (909) 698-9657. Good luck VInce _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: GeoMonitr@....... Subject: Re: HAM interested in earthquake prediction Date: Thu, 9 Oct 1997 12:28:09 -0400 (EDT) Yeah, as if quake predictors are right up there with Astrologers! Geez, when are you so-called scientists going to get an OPEN MIND!!?? Is it so inconceivable that precursors would have an electromagnetic component that a human or animal is capable of picking up? _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: GeE777@....... Subject: Re: HAM interested in earthquake prediction Date: Thu, 9 Oct 1997 14:17:51 -0400 (EDT) Hi Why don't we check it out. Have dog pounds keep track of how many dogs are lost and/or picked up each day. See if this number increases prior to an earthquake. That certainly can't be a very expensive experiment. n a message dated 97-10-09 12:31:02 EDT, GeoMonitr@....... writes: << Is it so inconceivable that precursors would have an electromagnetic component that a human or animal is capable of picking up? >> _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Rev. Bob Shannon" Subject: Re: HAM interested in earthquake prediction Date: Thu, 9 Oct 1997 13:51:29 -0700 (PDT) On Thu, 9 Oct 1997 GeoMonitr@....... wrote: > Is it so inconceivable that precursors would have an > electromagnetic component that a human or animal > is capable of picking up? When I was in my single digits back in the early 1950's I truly enjoyed building electronic projects...I felt that I could design some myself and it was the phase of life that led me to working in electronics for many years. Building and monitoring earthquake devices sounds like fun...and refining the instruments sounds like a bit of fun but maybe a bit more like drudgery.....On the other hand...attempting to figure out what sort of possible precursors could be causing 'signals' which humans could possibly be capable of receiving is even more exciting.... Let me example. I feel that ELF has a finger in this somewhere and so does Ben Parks of Placerville Ca. Ben has been following F-Smiths work and is a friend of his. Ben designed some pretty hefty A-D hard and software to monitor ULF and ELF. I have a ref. to him on my homepage.... I am wondering a bit with Vince, if it is at least in the same ballpark to monitor precursors as well as the actual quake...or at least make an attempt to discover the thread which ties them? Bob http://iea.com/~rshannon Rev. Robert Shannon Sr. Hon. DD Theology Pinpoint Newsletter "The web existed before spiders. The web existed before the net... We are all a part of the web and whatever we do to part - we do to the whole" ------------------------------------------------------------------ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Stephen Caruso Subject: Re: HAM interested in earthquake prediction Date: Thu, 9 Oct 1997 20:42:10 -0400 (EDT) I remember being in NW Wash. state in the mid 70's. I was on the road and settled down for the night. I remember hearing the animals around the area sounding distressed and then, boom, there was a tremor. The next night Iwas in someones house on the third floor and there was another yet stronger. On Thu, 9 Oct 1997 GeE777@....... wrote: > Hi > Why don't we check it out. Have dog pounds keep track of how many dogs are > lost and/or picked up each day. See if this number increases prior to an > earthquake. That certainly can't be a very expensive experiment. > > > > > n a message dated 97-10-09 12:31:02 EDT, GeoMonitr@....... writes: > > << > Is it so inconceivable that precursors would have an > electromagnetic component that a human or animal > is capable of picking up? > > >> > > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L STEPHEN CARUSO CET KB8UGH _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jim Hannon Subject: Re: HAM interested in earthquake prediction Date: Thu, 09 Oct 1997 20:24:08 -0500 Stephen Caruso wrote: > > I remember being in NW Wash. state in the mid 70's. I was on the road and > settled down for the night. I remember hearing the animals around the area > sounding distressed and then, boom, there was a tremor. The next night > Iwas in someones house on the third floor and there was another yet stronger. > > Hear is my story. :) I was in Iran in the 1960's when one of the big quakes struck. I distinctly remember the day before the quake I had a conversation with my dad about what to do if a quake happened. Chance or some sense -- I have no idea. Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N 91,39.26W WB0TXL _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: Mt Ruapehu "burps" Date: Fri, 10 Oct 1997 17:33:36 +1200 Hi all, Seismic activity has again started to rise below the crater lake of Mt Ruapehu (central Nth Is., New Zealand) after a 15 months of calm since the last large eruptions. Almost continuous harmonic tremor as well as individual events are 3 times up on the normal level of activity. And early am on the 10 Oct 97 NZST (late pm UTC 9 Oct.) the first small steam cloud was seen above the mountain. The Alert has been raised to level 2 on the international scale of 1 to 5, 5 being full maj. eruption 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: TMichel917@....... Subject: Streckeisen Date: Fri, 10 Oct 1997 15:08:38 -0400 (EDT) Hi Jean-Yves! Some time ago I read your mail concerning the Streckeisen seismometers. The Streckeisen STS-1 force-balance-seismometer is in its current version a "very-broad-band"-seismometer with a response flat to velocity from 0.1 to 360 sec period. It is only for observatory use. The mechanical design of the vertical sensor (STS-1V/VBB) is based on a semicircularly bent leaf spring which produces a very small and linear restoring force. The horizontal sensors (STS-1H/VBB) use pendulums of the "garden-gate"-type. The mechanics are shielded against variations in temperature, air pressure and magnetic field (only STS-1V/VBB). The external electronics use a combination of differential, proportional and integral feedback. The boom position is sensed by a LVDT (linear variable differential transformer) and the feedback force is generated by moving-coil transducers. The mechanics of the STS-2, which is also a force-balance-seismometer, are different from that of the STS-1 while the electronics are very similar. The STS-2 consists of three identical obliquely-oriented sensors in a single, sealed package. It is optimized for quick and simple installation. As boom position sensor the STS-2 uses a capacitive displacement sensor, the feedback force is generated by a moving coil transducer. Technical Data STS-1 Mechanical free period: Virtually infinite Response: Flat to ground velocity at a responsitivity of 2 x 1200 V sec/m Long period corner: 20 or 360 sec second order cutoff with 0.707 critical damping Short period corner: 0.1 sec Clip level: +/- 8 mm/s ground motion (0.1 - 360 sec) Dynamic Range: > 140 dB Prices: STS-1V/VBB appr. 17.000 SFr STS-1H/VBB appr. 12.500 SFr Technical Data STS-2 Mechanical free period: Virtually infinite Response: Flat to ground velocity with a responsitivity of 2 x 750 V sec/m Long period corner: 120 sec Short period corner: > 50 Hz Clip level: +/- 13 mm/s ground velocity Dynamic Range: > 140 dB Price: STS-2 appr. 19.000 SFr If you have any questions or need more information please feel free to contact me. Torsten _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: compare. of 3 sensors for Kermadec Date: Fri, 10 Oct 1997 15:04:19 -0700 At 08:28 PM 10/8/97 -0400, Bob Barns wrote: >Larry, > I downloaded 970920A.BKN, .LC1 & .LC3. of the Kermadec 6.9 event. >Thanks for taking the trouble of making files so that it is easy to compare >them. The comparison is very informative. (My great bad luck was to have >my rig down for this event--we had a power dip while I was out of town and >I had not provided for auto restart of SDR in AUTOEXEC.BAT.) [snip] > Since I have only a Lehman, I was delighted to see that yours was only >slightly inferior to the broadband rig. I suppose that the Berk. sensor is >in a good location (borehole?) so the similarity of the S/N must make you >feel good about your location. Information about the Berkeley sensor can be found at: http://www.seismo.berkeley.edu/seismo/bdsn/station_book/bks.html Its located in a vault, somewhere near the campus. My location is another story, and proves that you can record EQs in the city. I live a few hundred yards away from a major freeway (US 101) and to add insult to injury there is an industrial highway between my house and the freeway. On the other side of the house, about 1 1/2 mile away, are railroad tracks. For the last few months there has been some major construction work going on right down the street from me. For those of you who know the area they are demolishing the old Circle Star theater and building some office towers on the lot. When they where demolishing the theater my sensors where getting too 1/2 (~15k counts) the max counts of my 16 bit A/D converter. Now that the theater is gone, the noise during the day has reduced a little. I can see on my SDR system exactly when they stop for lunch etc. I can't wait from them to start there pile driving... They did a test one a few weeks ago and it sure drove my sensor, and my nerves (I work at home, so I'm around here when they do the work), crazy. > I have some questions:1. Since the S wave is very strong, how come the SS >and SSS seem to be absent? 2. The LQ calculates to be at about 16:56:12. >What is the nice 'blob' (do you have a better term for this?) centered at >about 16:51:48? This 'blob' has a period of about 23" and the sections >around the LQ and LR are about 16". I have a hard time seen any of the other phase myself. Not sure why... > I would greatly appreciate your repeating this exercise the next time we >have a teleseismic boomer--one which I should also get. Will do. > A suggestion for a new feature for WINQUAKE--how about a facility for >getting an RMS avg. value for a zoomed region? This would be a better >meas. of the background amplitude. Maybe you can think of something better >than RMS. I'll look into it. -Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: Ruapehu Date: Sat, 11 Oct 1997 18:07:37 +1200 Hi all, The mountain continues to increase in activity, Today (Sat 11 Oct97 NZ) the weather cloud cleared to show large billowing plumes of toxic gas clouds rising several thousand metres above the mountain. The rumbles/booms from the crater can be heard for several kilometres and at least one skifield is closing for safety. the others will prob. follow soon. The Alert level remains at "2" 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: prewar Subject: Three Dimensional Seismograph, thoughts, and a poem! Date: Sun, 12 Oct 1997 10:15:53 +0100 Hello everyone, from the other side of the 'BIG POND'! I have just joined PSN and have started reading the archives.... WOW, it takes some time, doesn't it? As we don't suffer any large events here in England, I am using single pivot points for hor. pendulums...... Pivots are 1930's gramophone needles (which have SMOOTH, hard ground ..005 " radiused tips), sitting into hardened domed anvils, on the horizontal pendulums. (Two-90 degree opposed, for NS and EW orientation). Attempting to get swing periodicity of 60 SECONDS..... somewhat difficult to obtain with beam lengths of only 24 inches. (The vertical offset required calculates out to only .01 inches!) .015 piano wire suspension. >>>> HAS ANYBODY TRIED USING CARBON FIBRE FOR SUSPENSION? WOULD IT STRETCH? <<<<<< With a vertical seismo in-tow with the 2 horizontals, I hope to have a Three-Dimensional seismograph. Software will show SECTIONS both through earth NS and EW, and also PLAN of earth movements, in addition to normal o/p traces on VDU etc. All Hall-Effect sensing + 12 bit A/D. RE YOUR PREVIOUS CHATS ON SEISMO ADJUSTMENTS, to keep pivot points aligned EXACTLY vertically below suspension as viewed from front..... I got hold of some .75" dia ball races with a small slot ground in the o/d. These are clamped in a 3/8 bolt. (with 2 nuts each side of race) The ball race 'bolt' is horizontally mounted at top of upright, (where the piano wire is normally anchored) into a 3/8 tapped hole, and the piano suspension goes OVER the race, IN THE SLOT, and is anchored lower down, (using yet another bolt and a thrust race for up/down adjustment to wire/beam). All this gives fine ALL ROUND adjustments to beams. The bolt thread mustn't be course for smooth adjustment...(> 30 TPI). Planning to use 20x50ohm resistors in series on 240v mains, to GENTLY heat seismo enclosure....each R giving off 3watts, keeps to 75 degreeF in winter. Does anyone have any criticism/comment on this type of heating, please???? Someone mentioned last March that heat should be positioned at TOP of enclosures. ANY comment on anything above would be appreciated. I shall study your archives further. It's all very interesting. But for now, as many of you folk seem to be interested in astronomy as well as seismology, you may like to read my own SHORT, philosophical poem about these fields....... W H E N. When the earth trembles I shall be aware. When a star twinkles I shall sit and stare. When oblivion takes me I shall not care........ For in Earth AND in Heaven, I have been there. Prewar Albert Noble. Regards to all, 'over there'. (and ANYWHERE else!) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: steve jones Subject: Address for Oregon Scientific? Date: Sat, 11 Oct 1997 09:21:44 -0700 Does anyone have a telephone number / email address / etc. to reach Oregon Scientific? Thanks in advance! Steve Jones _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: bfryer@............ (Bob Fryer) Subject: Re: Address for Oregon Scientific? Date: Sat, 11 Oct 1997 07:53:08 -0700 (PDT) Hi Steve, Address: 18383 SW Boones Ferry Rd. Tigard, OR 97224 (503) 639-8883 Bob -- Beaverton, OR -- on the Cascadia Subduction Zone >Does anyone have a telephone number / email address / etc. to reach >Oregon Scientific? Thanks in advance! > >Steve Jones ----- earthquake WARNING research ----- --- animals, people, scientific evidence --- --- http://www.teleport.com/~bfryer --- _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert Avakian Subject: Re: HAM interested in earthquake prediction Date: Sat, 11 Oct 1997 19:52:17 -0700 Someone help me on this, but I am sure I reember the Chineeses having at least one success warning of a major quake by monitoring the behavior of flocks of ducks in the area's villages. Was this success ever reperted? Or was it serendipity? Alsso, i remeber seeing a piece on TV about the guy in LA who predicts quakes by, among other things, the number of lost pet ads in the papers. Bob GeoMonitr@....... wrote: > > Many people have been trying to duplicate the experiments > of Anthony Fraser-Smith at Stanford, by detecting > ULF signals that may be a link between earthquake > precursors and human reactions. > > I started a newsletter on the subject, GeoMonitor, > and I have all 6 years of back issues, including some > amateur circuits for ULF detection. The newsletter is now > being published by Charles Patton, 21490 Camino Arriba, > Murrieta, CA 92562; (909) 698-9657. > Good luck > VInce > > _____________________________________________________________________ > > 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: "Erich F. Kern" Subject: Drum Recorders Date: Sat, 11 Oct 1997 20:28:26 -0700 Hi All, Does anyone have a drum recorder they'd like to sell? Am willing to refurbish to some extent, but it must have the pen driver and major components. Will pick up in So. California. Please respond to my e-mail address and NOT to this list. Regards, Erich Kern ekern@......... *************************************************************** Please visit our web site at: http://www.dconn.com/FatQuartersSoftware Thank you ************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: Ruapehu update Date: Sun, 12 Oct 1997 17:13:23 +1200 Ruapehu today (Sun 12 Oct. NZ) did a throat clearing with its first ash eruption in this current burst of activity. The action was captured on video tape by TV news cameramen who were near the summit at the time. The Alert Level remains at 2 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: prewar Subject: Re: HAM interested in earthquake prediction Date: Sun, 12 Oct 1997 09:21:07 +0100 Hi, See Bruce Bolts book, 'Earthquakes and Geological Discovery'. Pub1993 by Scientific American Library. Chapter 8...'Forcasting Earthquakes'. (geologist in San Franscisco bay area, DID predict using lost animals!!) ....See page 182. Hope this helps. Regards, Albert Noble, (England). Robert Avakian wrote: > Someone help me on this, but I am sure I reember the Chineeses having at > least one success warning of a major quake by monitoring the behavior of > flocks of ducks in the area's villages. Was this success ever > reperted? Or was it serendipity? > > Alsso, i remeber seeing a piece on TV about the guy in LA who predicts > quakes by, among other things, the number of lost pet ads in the papers. > > > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Karl Cunningham Subject: Re: Three Dimensional Seismograph, thoughts, and a poem! Date: Sun, 12 Oct 1997 08:34:20 -0700 Greetings Prewar -- Glad to have you in the group. I'll try to comment/answer a couple of things you mentioned... >to keep pivot points >aligned EXACTLY vertically below suspension as viewed from front..... I do this by getting it close mechanically, then changing the level of the entire instrument for the final adjustment. Do you think there is a difference in performance using one technique vs. the other? >Planning to use 20x50ohm resistors in series on 240v mains, to GENTLY >heat seismo enclosure....each R giving off 3watts, keeps to 75 degreeF >in winter. Does anyone have any criticism/comment on this type of >heating, please???? Someone mentioned last March that heat should be >positioned at TOP of enclosures. ANY comment on anything above would >be appreciated. Am I understanding you correctly that you will have 60 watts total? I use 2 watts total for the heater, mounted at the top, and my enclosure is insulated on all sides except the bottom by about 2" of urethane foam. I believe the idea is to stratify the air inside the enclosure in order to reduce convection currents as much as possible. I have all the electronics located outside the enclosure to avoid convection from that. With the heater mounted at the top, the air should be the warmest at the top and coolest at the bottom, forming a smooth gradient in between. This gradient is hopefully due to mostly conduction and minimally convection. I haven't tried it, but I suppose it would be helpful to shield the heater in such a way as to minimize radiation to components below it. Hope this helps. Karl Cunningham La Mesa, CA. PSN Station #40 karlc@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Clark Wockner Subject: detect ble distance Date: Sun, 12 Oct 1997 13:06:11 -0700 Hi all: I seem to be missing most of the quakes others are getting. Is it because most seismic zones are so far from Illinois or is it because of some other reason? I did not record the Kermadek 6.9 a while back and I was sure I should have gotten it. What kind of distance are the rest of you getting with your Lehmans? Comments please. Thanks all Clark _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: detect ble distance Date: Sun, 12 Oct 1997 00:08:33 -0700 Hi Clark I live on the west coast. I can pick up 6.5 events @ 9000k most of the time. I would guess you're another 3000k to the east. It depends on how high you can get away with setting your gain and howfar you are away from the epicenter. I think where your sensor is located locally could have an effect on recording but I don't think that should affect the large teleseismic events. Most event files I've seem are < 11,000k away. I guess you will have to do the math from your location. It seems maybe you would have better luck picking up events from the east ,eg Italy,middle east etc. There are "dead" zones which others have mentioned and could probably explain there angle range better than I. I miss events because I run on a trigger system. Others use continuous recording. Which do you have? I hope that helps a little. Barry >Clark Wockner wrote: > > Hi all: > I seem to be missing most of the quakes others are getting. Is it > because most seismic zones are so far from Illinois or is it because of > some other reason? I did not record the Kermadek 6.9 a while back and I > was sure I should have gotten it. What kind of distance are the rest of > you getting with your Lehmans? Comments please. > Thanks all > Clark > > _____________________________________________________________________ > > 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: Three Dimensional Seismograph, thoughts, and a poem! Date: Sun, 12 Oct 1997 14:50:25 -0500 prewar wrote: > With a vertical seismo in-tow with the 2 horizontals, I hope to > have a Three-Dimensional seismograph. Software will show SECTIONS both > through earth NS and EW, and also PLAN of earth movements, in addition > to normal o/p traces on VDU etc. All Hall-Effect sensing + 12 bit A/D. > I would be very interested in hearing more about how you plan on viewing the 3d data. I am working on a 3 axis instrument with each axis having identical response. But I haven't any good ideas on viewing the data. -- Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N 91,39.26W WB0TXL _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: TESMECO@....... Subject: Re: Ruapehu update Date: Sun, 12 Oct 1997 18:54:25 -0400 (EDT) thanks to you i am getting interested in this one i like the daily up dates thanks _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: electronic oscillator Date: Sun, 12 Oct 1997 09:47:43 -0700 Hi All I have one for you . Bare with me. I would like to increase the period of a Lehman . I made a phase shift oscillator to represent an electronic pendulum. With a gain below unity, I got damping. The period of the oscillator was determined by the resistors and capacitors used. I put an external input to oscillator by attaching a coil of magnet wire. By bringing a magnet near the coil I could get the oscillator to oscillate and damp out just like an excited pendulum. I would like to replace the coil with a displacement device like an LVDT. I would then mount the LVDT on the end of a "garden gate". I would then set the natural frequency to as low as I like, electronically. The output of the oscillator would be feed back to the garden gate by a second coil, thus making the garden gate respond like the electronic oscillator. The LVDT could be measured or a third coil could be used to represent the Lehman's velocity sensor. Sound pretty Rube Golberg, but would it work? Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "David A. Nelson" Subject: Re: Ruapehu update Date: Mon, 13 Oct 1997 17:27:28 +1200 Hi ??, I don't know your name as you didn't sign your mail, there are a lot of us who are whish that this mountain would do a proper throat clear and really blow its top.... the last really major eruption ( say on the scale of Mt. St.Helens) from a New Zealand volcano was in 1886 when Mt. Tarawera, ~100km nth of Ruapehu, let rip causing deaths and much damage to the Native Maori and early European settlements in the region at that time. As far as I am aware it is the only eruption to cause direct loss of life in modern times. A non-eruption related lahar from Mt. Ruapehu, christmas, 1953 wiped out a railway bridge causing the passenger train to plunge to destruction with the loss of 151 lives. this was caused by ash from a small eruption, several years earlier, blocking the outlet from the crater lake and as the lake level rose the ash dam finally burst sending a huge lahar down the river. Dave At 06:54 PM 10/12/97 -0400, you wrote: >thanks to you i am getting interested in this one i like the daily up dates >thanks > 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: prewar Subject: Heating enclosures and multi-seismos. Date: Mon, 13 Oct 1997 12:42:01 +0100 Hi Karl, Many thanks for reply.....my FIRST contact outside England.....been on internet only 3 weeks, so please excuse if protocol isn't quite correct. I have to use my idea, re ball races adjust. as I have BOTH hor. Pendulums on same frame...using normal method would put one out of line, when adjusting the other, and so on. In fact, the VERTICAL seismo is also on same frame... perhaps I have troubles to come!! It was common practice many years ago to have multi-seismo mountings, so for convenience sake, I have done this. Hasten to add that frame upright is 1"x1" steel, AND braced, so its anti-flexing! Yes, 60W is correct...I have a heated insulated hut, and inside it, is a further insulated enclosure which houses 3 seismos....60W required in winter to keep this enclosure to 75F, thermostatically controlled. I assume that your own enclosure is small, or ELSE your winters are very mild, as you only need 2W. Rather nice to be so low. Noted that your heat is from TOP. I was going to put my R's all around BOTTOM perimeter, but perhaps not, after your comment. Yes, would have thought any DIRECT heat onto seismos is to be avoided at all costs. I couldn't really believe, sitting in my little hut, in the middle of England, in a tiny village, that someone half way around the world would reply. Am finding the archives a great source of info and experience... ....still reading through them ALL! (shall never have time now to get my 3 seismo monsters working!) Many thanks again for comments/advice, Regards. Albert Noble. Karl Cunningham wrote: > Greetings Prewar -- > > Glad to have you in the group. I'll try to comment/answer a couple of > things you mentioned... > > >to keep pivot points > >aligned EXACTLY vertically below suspension as viewed from front..... > > I do this by getting it close mechanically, then changing the level of the > entire instrument for the final adjustment. Do you think there is a > difference in performance using one technique vs. the other? > > >Planning to use 20x50ohm resistors in series on 240v mains, to GENTLY > >heat seismo enclosure....each R giving off 3watts, keeps to 75 degreeF > >in winter. Does anyone have any criticism/comment on this type of > >heating, please???? Someone mentioned last March that heat should be > >positioned at TOP of enclosures. ANY comment on anything above would > >be appreciated. > > Am I understanding you correctly that you will have 60 watts total? > > I use 2 watts total for the heater, mounted at the top, and my enclosure is > insulated on all sides except the bottom by about 2" of urethane foam. I > believe the idea is to stratify the air inside the enclosure in order to > reduce convection currents as much as possible. I have all the electronics > located outside the enclosure to avoid convection from that. With the > heater mounted at the top, the air should be the warmest at the top and > coolest at the bottom, forming a smooth gradient in between. This gradient > is hopefully due to mostly conduction and minimally convection. I haven't > tried it, but I suppose it would be helpful to shield the heater in such a > way as to minimize radiation to components below it. > > Hope this helps. > > Karl Cunningham > La Mesa, CA. > PSN Station #40 > karlc@....... > > _____________________________________________________________________ > > 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: Heating enclosures and multi-seismos. Date: Mon, 13 Oct 1997 23:56:40 +1200 Albert Did you think about just using a 60W lightbulb, If your enclosure is metal you could put a perspex window in it and the light would let you keep an eye on the inside without having to remove the cover. Dave _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "James M Hannon" Subject: Re: electronic oscillator Date: Mon, 13 Oct 1997 07:25:55 -0500 I have been thinking about a similar concept for some time. Here are some additional thoughts. What determines the mechanical period of the pendulum is the rate at which the "restoring" force increases with displacment from rest. If one were to adjust the pivot alignment so that there was no mechanical restoring force then one could replace the mechanical force with a magnet and coil being fed from the LVDT output. By adjusting the gain of this circuit one could in theory set the period to any value desired. A big problem that I see with this is that the mechanical adjustments are very minute and subject to all sorts of outside infuuences. Unless the electronics can somehow compensate for these infulences things won;t work too well. Jim Hannon gbl@....... on 10/12/97 11:47:43 AM Please respond to psn-l@............. To: psn-l@............. cc: (bcc: James M Hannon/CedarRapids/Collins/Rockwell) Subject: electronic oscillator Hi All I have one for you . Bare with me. I would like to increase the period of a Lehman . I made a phase shift oscillator to represent an electronic pendulum. With a gain below unity, I got damping. The period of the oscillator was determined by the resistors and capacitors used. I put an external input to oscillator by attaching a coil of magnet wire. By bringing a magnet near the coil I could get the oscillator to oscillate and damp out just like an excited pendulum. I would like to replace the coil with a displacement device like an LVDT. I would then mount the LVDT on the end of a "garden gate". I would then set the natural frequency to as low as I like, electronically. The output of the oscillator would be feed back to the garden gate by a second coil, thus making the garden gate respond like the electronic oscillator. The LVDT could be measured or a third coil could be used to represent the Lehman's velocity sensor. Sound pretty Rube Golberg, but would it work? Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: prewar Subject: Re: THREE DIMENSIONAL Seismograghs and software. Date: Mon, 13 Oct 1997 13:32:50 +0100 Hi Jim, T H R E E D I M E N S I O N S. I was very interested to hear that you too are building a three axis seismo 'cluster'. I do not know what sort of software you run...is it home brew, or off the shelf? What language are you running I wonder. I have to confess that I only use a 'souped up' version of BBC BASIC....B U T, it has a smashing built in assembly language facility, which can be used for any nitty gritty fast programing. In addition to all the normal seismo programming on my PC, keyboard selection to show any of the following... 1......All 3 traces from o/p of NORTH/SOUTH, EAST/WEST and VERTICAL seismos shown TOGETHER, (each one in a different colour.) 2......Above, but seperate. 3......A large full screen draw of a PLAN VIEW of earth. The NS seismo o/p controlling the vertical component of the trace, and the EW seismo controlling the horizontal. 4.......As 3 but section through earth parallel with equator. EW seosmo o/p controls horizontal draw and VERTICAL seismo, the vertical of course. 5.......As 4 but section through earth from pole to pole. This time EW seismo o/p controls horizontal and as above, and the vertical seismo, the vertical. 6........3,4 and 5 above on screen together ,(but smaller plots of course). 7........2,3,4 and 5 all on screen together, (with even smaller plots.). 8........Have an automatic rain gauge installled ( tipping bucket design). PC sums rainfull each day and shunts it to HD....Screen can also show bar graph of rain on daily/month/yearly basis. (my PC won't yet do the washing up ..... .....but I'm working on it!!) As my seismos are not yet working, I have carried out SIMULATION on my PC program, using randomly generated values for 3 seismos and all seems OK. One thing I found was that unlike the normal o/p trace, when showing 3 to 6 above, and when there is little activity. As one is constantly drawing and redrawing a trace over the same area, then confusion begins to reign on the screen. I found that this can be partly overcome by changing the colour of the draw each time the o/p from the 3 seismos is read. (in my case 50 times per sec). This gives a multi-coloured plotting which is better than using just white on a black backgnd. (Colours are randomly selected by the PC, each conversion). Also one could automatically increase the SIZE of drawings, during quiet periods......... The o/p from seismos (if 12 bit), must be divided down to fit in with the number of pixels on the screen mode used.....12bit gives over 4096 posible positions, and it is unlikely that 4096 pixels are available on PC, X or Y axis.. For example, I have +10v, 12 bit A/D converter, sampling each seismo in turn. So 5v pos o/p gives me values up to 2048. For development work I use 640x480 screen mode......so 2048 must be divided by 4 = 512. Each increment step in A/D conversion is now represented by 1 pixel with some screen area to spare. eg. 1000 o/p divided down is 250. Say next conversion reads 900. (900/4=225). SO, program draws coloured line now on VDU, from position 250 to 225. Next conversion from 225 to next position, and so on. PLEASE EXCUSE if any of this is ground you are very familiar with. Well Jim, I hope this will give you some food for thought, and help a bit. You've hit upon my FAVOURITE seismo topic.....final aim is to have 3 D hologram, showing 3D movement of earth particals, in real time or speeded up.....will probably start with a suspended table tennis ball attached to 3 servo motors . I first become interested in the above when I read a book on seismology written by the father of English seismology, Prof. Milne, in 1898 (!!). He used smoked glass to record upon, and produced great traces showing the movement of the earth as seen from above. I thought that my PC was better equiped than smoked glass , so that is what started me down this particular road to Three Dimensions. Happy T H R E E-DIMENSIONAL SEISMO'ING!! .. Regards, Albert Noble. Jim Hannon wrote: > prewar wrote: > > > With a vertical seismo in-tow with the 2 horizontals, I hope to > > have a Three-Dimensional seismograph. Software will show SECTIONS both > > through earth NS and EW, and also PLAN of earth movements, in addition > > to normal o/p traces on VDU etc. All Hall-Effect sensing + 12 bit A/D. > > > > I would be very interested in hearing more about how you plan on viewing > the 3d data. I am working on a 3 axis instrument with each axis having > identical response. But I haven't any good ideas on viewing the data. > > -- > Jim Hannon > http://soli.inav.net/~jmhannon/ > 42,11.90N 91,39.26W > WB0TXL _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: prewar Subject: Re: Heating enclosures. Date: Mon, 13 Oct 1997 13:44:25 +0100 Hello Dave, Yes, I have an acrylic frontage to the enclosure, but many have pointed out that my heating is excessive, so I am having a rethink. I thought that 1 lightbulb would give too concentrated a heat.....I do use 4x40w light bulbs to heat my insulated hut though, but the seismos are seperately enclosed. Thanks for suggestions from you, and all. Regards, Albert Noble (England) David A. Nelson wrote: > Albert Did you think about just using a 60W lightbulb, If your > enclosure is metal you could put a perspex window in it and the light > would let you keep an eye on the inside without having to remove the cover. > > Dave > > _____________________________________________________________________ > > 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: Doug Crice Subject: Re: Heating enclosures. Date: Mon, 13 Oct 1997 08:21:02 -0700 re: Heating your seismometers I would think it would be better to use DC instead of AC to heat seismometers, at least if anybody has problems with 50/60 Hz noise. I also think that a variable resistance temperature control would be better than a thermostat, both to keep the temperature constant and to eliminate the transient from the switch. There are some relatively cheap thermistors big enough to do this job in electronics catalogs. Doug Crice _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Charles R. Patton" Subject: Re: Heating enclosures. Date: Mon, 13 Oct 1997 10:00:26 -0700 Another thought for self regulating heaters is to use PTC's (also called Posistors). This is becoming the mechanism of choice for coffee brewers. The PTC is self limiting in temperature. So it smoothly transitions to a given temperature which is set by the design of the PTC itself. No EMI! They're not terribly accurate, but they are simplicity themselves. For instance I looked up one available PTC heater from Keystone Thermometrics, St.Marys, PA 15857, phone 814-834-9140 and 800-246-7019. A part number 5510-25-65-120-PTH is a 120 V 65 degree C 20 W disc .55" dia and 0.1" thick. Another company in addition to Keystone that I'm aware of that makes heater type PTC's and that you might have some luck with in small quanities is Therm-O-Disc, Inc., Midwest Components Product Group, Muskegon, MI phone 616-777-4100. I also believe TDK, Murata, and Philips components among others, make heater versions of PTC's, but they are hard to deal with unless you have a volume application or work for a big company where the salesman can slip you some samples. There are many others that supply instrument size PTC's for use in sensing applications and certain types of current limiting and resettable fuse applications. I know I've seen some of the surplus catalogs with the coffee pot elements for sale. The problem here is that they are probably set for about 120 degrees C. A bit high for your use. Electronic parts store that cater to the TV repair area usually had some PTC's that were used on color TV sets to control the deguassing coil. They would allow an amp or two to flow for a few seconds when the TV was first turned on, then due to self heating would shut down to a few milliamps while the set remained on. What their setting temperature was, I have no idea -- just the place for a quick experiment, don't you think? Anyway, good luck. Charles R. Patton _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Roger Baker Subject: Re: Heating enclosures. Date: Mon, 13 Oct 1997 12:06:39 -0500 Friends, With respect to most sensitive, high resolution instrumentation, thermal drift is the #1 problem limiting measurement accuracy. Two main design options for temperature control are a variable resistor, usually a transistor in series with the heater -- versus pulse width modulated heating which is actually a very rapid on-off control. The latter is very efficient since there is very little resistive heating in the control transistor, since the power is either full on or off. You can often operate this circuit above the top frequency of the sensor. (With very small sensor packages, the transistor itself can be used as a heater, which is both convenient and efficient.) My current approach for moderately sized sensors such as my *jellybean* seismometer/gravimeter is to use pulse width modulated heaters. The heater is arrays of evenly spaced small 100 ohm or so resistors glued with silicone to the outside of the aluminum box sensor enclosure, which is then encased in styrofoam. The best temperature control and uniformity comes from having alternating layers of good thermal conductors like aluminum and poor thermal conductors like styrofoam. If possible, try to design for small size because gradients and other thermal problems increase rapidly with instrument size. Put your front end electronics in the same thermally controlled box with the sensor. Attach your thermal sensor directly to part of the heater so the thermal lag of the feedback loop is minimized. The accuracy of the system is often increased is there is standby power going into the heater so the control power merely power tops off this constant level of heat input. Also you can't get good thermal control with a low gain feedback loop; accuracy is increased as you turn up the electronic gain of the thermal feedback loop -- usually until the system becomes unstable and starts hunting or oscillating in temperature. For REALLY precise temperature control, there is not much alternative but to use several concentrically enclosed stages of rough control and precision control. Standard little Radio Shack thermistors can probably be made to sense levels of microdegrees near room temp with appropriate support circuitry and seem to work plenty well enough for most practical sensing purposes such as thermal feedback controls. --Yours, Roger Baker _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: prewar Subject: Re: Heating enclosures. Date: Mon, 13 Oct 1997 16:45:39 +0100 Yes Doug, Hadn't thought about AC noise....now having a rethink here. Thanks for advice from you, and everyone else, who responded to my first letter. Regards...Albert Noble. Doug Crice wrote: > re: Heating your seismometers > > I would think it would be better to use DC instead of AC to heat > seismometers, at least if anybody has problems with 50/60 Hz noise. I > also think that a variable resistance temperature control would be > better than a thermostat, both to keep the temperature constant and to > eliminate the transient from the switch. > > There are some relatively cheap thermistors big enough to do this job in > electronics catalogs. > > Doug Crice > > _____________________________________________________________________ > > 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: Brian Chesire Subject: Re: Heating enclosures. Date: Mon, 13 Oct 1997 11:31:23 -0700 Hi, A fairly good temperature contoller is the National LM3911. I've used these for everything from milliwatt heaters to 6.5KW heaters. Very versatile. The National data sheet covers it pretty well. Properly designed it can give you a very tight loop. However, When I needed really tight control, at temps over 80C, I used a pretty standard thermistor proportional circuit. This was for a precision oscillator, ie. crystal oven. The LM3911 controls the outer oven, at 55C, and the thermistor the inner. The control circuitry for the inner oven is mounted inside the outer oven which really helps overall stability. Brian, Tucson, AZ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Daryl P. Dacko" Subject: Re: Heating enclosures. Date: Mon, 13 Oct 1997 19:19:12 -0400 At 10:00 AM 10/13/97 -0700, you wrote: >Another thought for self regulating heaters is to use PTC's (also called >Posistors). This is becoming the mechanism of choice for coffee >brewers. The PTC is self limiting in temperature. So it smoothly >transitions to a given temperature which is set by the design of the PTC >itself. No EMI! They're not terribly accurate, but they are simplicity >themselves. I've used them myself to regulate temperature on a drift-sensitive transister. They work just fine if you don't need very percise control, although I've seen mine control to within .1 deg C in an insulated oven. If you want more BTU's, just thermally bond them to a heatsink located near the top of the box. I know Newark Electronics carrys them, and for the folks overseas, Farnell could likely get them too, since they are the same company... A great idea, I didn't think of useing them in this application. It's a real boon to us folks where it's blistering hot in the summer and bitter cold in the winter - automatic heat without the expensive controller ! Daryl _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: detectable distance Date: Mon, 13 Oct 1997 15:33:26 -0700 At 01:06 PM 10/12/97 -0700, Clark Wockner wrote: >Hi all: > I seem to be missing most of the quakes others are getting. Is it >because most seismic zones are so far from Illinois or is it because of >some other reason? I did not record the Kermadek 6.9 a while back and I >was sure I should have gotten it. What kind of distance are the rest of >you getting with your Lehmans? Comments please. > Thanks all > It could just be the distance, but you should also check the period of your sensor. If its not long enough you will not pickup the long period surface waves. I had this problem with my Lehman a while back. I wasn't getting much low freq. information so I checked the period. Sure enough, it was down to something like 6 seconds. It should have been around 16 to 20 seconds. It must have changed do to all of the re-adjustment I keep having to do to it, do to the tilting problem. -Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: TESMECO@....... Subject: Re: Ruapehu Date: Mon, 13 Oct 1997 21:04:06 -0400 (EDT) looking forward to see if it will blow i hope there isnt any body to close when and if it dose thans for the history TIM. SO CAL _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: THREE DIMENSIONAL Seismograghs and software. Date: Mon, 13 Oct 1997 06:58:09 -0700 Hi All I haven't been following the Three Dimensional thread in detail but I think (in theory) if one has the three components of an arriving wave that it should be possible to determing the direction the wave is coming from by vector analysis. With the addition of the arrival times, one could "pinpoint" the epicenter from one station. In reality I think the waves from three directions could get pretty complicated for other than local events. Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Al Allworth Subject: Re: Heating enclosures. Date: Mon, 13 Oct 1997 19:06:58 -0700 (PDT) At 12:06 PM 10/13/97 -0500, you wrote: > >Friends, > With respect to most sensitive, high resolution instrumentation, >thermal drift is the #1 problem limiting measurement accuracy. > Hello group, 25 years ago I designed a temperature control which might be of interest here. The company I was working for determined the circuit to be patentable but the project we were working on was canceled and the rights were assigned to me. I didn't have the money to patent it and people were not using accurate ovens for electronics circuits any more so it never went anywhere. The temperature sensor and the heating element are one and the same. The heater is in the form of a bridge with oposite legs made of Iron wire and the other pair of Manganin wire, which has close to zero temperature coeficient. The midpoints of the bridge are connected to a diferential amplifier which drives a series transistor feeding the bridge heater from the power supply. I was able to get a temperature stability with a single enclosure of better that 1/10 of a degree with the outside temperature changing from 0 degrees to 75 degrees F. I would be happy to see someone put this to practical use. Al _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: JIM CRISTIANO Subject: Re: detectable distance Date: Mon, 13 Oct 1997 20:36:16 -0700 Larry Cochrane wrote: > It could just be the distance, but you should also check the period of your > sensor. If its not long enough you will not pickup the long period surface > waves. I had this problem with my Lehman a while back. I wasn't getting > much low freq. information so I checked the period. Sure enough, it was > down to something like 6 seconds. It should have been around 16 to 20 > seconds. It must have changed do to all of the re-adjustment I keep having > to do to it, do to the tilting problem. Nothin' like an old wood floor for some ultra slow rockin' and rollin'! Jim cristiano@........... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "David A. Nelson" Subject: New Station on the USA map Date: Tue, 14 Oct 1997 20:41:41 +1200 Hi all, Please welcome Robert Laney from Herndon, Va, to the group. It's good to see another east coast seismic station up and running, look for him on the USA map on my pages. 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: "David A. Nelson" Subject: MONSTER QUAKE STH PAC Date: Tue, 14 Oct 1997 22:08:13 +1200 _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Stephen Paul Subject: Re: MONSTER QUAKE STH PAC Date: Tue, 14 Oct 1997 03:50:26 -0700 Dave-- What happened in the South Pacific. I am VERY concerned about anything down there, as contrary to popular theory I sincerely believe in the 'ringing bell' hypothesis, and that anything big that happens on the west side of my little Pacific plate can and will have repercussions over here in LA to NW on the other side of the rim.... Any info yet? Stephen :^) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "David A. Nelson" Subject: Re: MONSTER QUAKE STH PAC Date: Tue, 14 Oct 1997 23:03:58 +1200 Stephen, still waiting for posting to USGS bulletin page. event ~5.5 minutes from my which puts it in the New Calidonia =---- Fiji regional distance and the amplitude suggests M7.9 --- 8.5 largest amplitude I have recorded for this distance. Tony in Hawaii mailed me a short time ago He also recorded it with large amplitude (largest he has so far recorded Dave At 03:50 AM 10/14/97 -0700, you wrote: >Dave-- > >What happened in the South Pacific. I am VERY concerned about anything >down there, as contrary to popular theory I sincerely believe in the >'ringing bell' hypothesis, and that anything big that happens on the west >side of my little Pacific plate can and will have repercussions over here >in LA to NW on the other side of the rim.... > >Any info yet? > >Stephen :^) > > > >_____________________________________________________________________ > >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: peaches@............ (Donna Whitaker) Subject: Re: MONSTER QUAKE STH PAC Date: Tue, 14 Oct 1997 01:17:11 -1000 (HST) Dave, CDIDC has it in the Fiji Islands region at M6.2 but thats got to be way low. Tony >Stephen, > still waiting for posting to USGS bulletin page. > > event ~5.5 minutes from my which puts it in the New Calidonia =---- Fiji >regional distance and the amplitude suggests M7.9 --- 8.5 largest >amplitude I have recorded for this distance. > > Tony in Hawaii mailed me a short time ago He also recorded it with >large amplitude (largest he has so far recorded > >Dave > > >At 03:50 AM 10/14/97 -0700, you wrote: >>Dave-- >> >>What happened in the South Pacific. I am VERY concerned about anything >>down there, as contrary to popular theory I sincerely believe in the >>'ringing bell' hypothesis, and that anything big that happens on the west >>side of my little Pacific plate can and will have repercussions over here >>in LA to NW on the other side of the rim.... >> >>Any info yet? >> >>Stephen :^) >> >> >> >>_____________________________________________________________________ >> >>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) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: lahr@................. (Dr. John Lahr (USGS-GI Seismologist)) Subject: Monster Quake Date: Tue, 14 Oct 1997 03:27:59 -0800 Here is what Palmer, Alaska, got. JCLahr > From atwc@.......... Tue Oct 14 03:12:41 1997 > From: atwc@.......... > Date: Tue, 14 Oct 97 10:44:59 GMT > To: tsunami@.............. thomasville.moc@......... > incident_information_@................ alert@........... > oemd@................ ecc@.......... > tsunami_&_pacific_eqs@................ Mary.Edwards@......... > ap@........... pamela_bergmann@............ jstorm@.................. > atwc@.................. avo-Anc@................... aeboro@........... > oes@.............. 0001032943@............ > bob_stewart@.................... R7AIUWR@............. > editor@........... havinfun@........... kiro@............ > paul@................. lrayment@.......... lad1@................. > gfdurocher@......... ruth.barritt@......... watson@................. > char@............... bgoldenberg@.............. marlins@........... > Cc: atwc@.......... > Subject: Tsunami Bulletin > > > > > TSUNAMI BULLETIN NUMBER 1 > WEST COAST AND ALASKA TSUNAMI WARNING CENTER/NOAA/NWS > ISSUED OCT 14 AT 1041 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 7.1, OCCURRED AT > 0153 ADT ON OCT 14, OR 0253 PDT ON OCT 14, OR 0953 UTC ON OCT 14. > THE EARTHQUAKE WAS LOCATED IN THE GENERAL AREA OF: > TONGA IS. NEAR 21.9S, 176.7W. > 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. > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "David A. Nelson" Subject: Re: MONSTER QUAKE STH PAC Date: Tue, 14 Oct 1997 23:39:43 +1200 I have been fooled in the past..... sometimes on a really deep event you get larger amplitude because of the lower attenuation between the epic and my recorder as a result a questimate mag. that is a bit high but M6.2 seems too low for this distance one that size and dist. would only just be detectable for me. plus I suspect that it may not be extremely deep as I recorded the LR (Rayleigh) surface waves I'm still picking the final result will be in the high 7's a bit dangerous to put money on it though..... Dave At 01:17 AM 10/14/97 -1000, you wrote: >Dave, >CDIDC has it in the Fiji Islands region at M6.2 >but thats got to be way low. > >Tony 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: "David A. Nelson" Subject: Re: Monster Quake Date: Tue, 14 Oct 1997 23:46:59 +1200 Thanks John, USGS bulletin just released 97/10/14 09:53:18 21.95S 176.92W 166.2 6.5Mb FIJI ISLANDS REGION SE of Fiji in the Tongan Is. Dave At 03:27 AM 10/14/97 -0800, you wrote: >Here is what Palmer, Alaska, got. > >JCLahr > >> From atwc@.......... Tue Oct 14 03:12:41 1997 >> From: atwc@.......... >> Date: Tue, 14 Oct 97 10:44:59 GMT >> To: tsunami@.............. thomasville.moc@......... >> incident_information_@................ alert@........... >> oemd@................ ecc@.......... >> tsunami_&_pacific_eqs@................ Mary.Edwards@......... >> ap@........... pamela_bergmann@............ jstorm@.................. >> atwc@.................. avo-Anc@................... aeboro@........... >> oes@.............. 0001032943@............ >> bob_stewart@.................... R7AIUWR@............. >> editor@........... havinfun@........... kiro@............ >> paul@................. lrayment@.......... lad1@................. >> gfdurocher@......... ruth.barritt@......... watson@................. >> char@............... bgoldenberg@.............. marlins@........... >> Cc: atwc@.......... >> Subject: Tsunami Bulletin >> >> >> >> >> TSUNAMI BULLETIN NUMBER 1 >> WEST COAST AND ALASKA TSUNAMI WARNING CENTER/NOAA/NWS >> ISSUED OCT 14 AT 1041 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 7.1, OCCURRED AT >> 0153 ADT ON OCT 14, OR 0253 PDT ON OCT 14, OR 0953 UTC ON OCT 14. >> THE EARTHQUAKE WAS LOCATED IN THE GENERAL AREA OF: >> TONGA IS. NEAR 21.9S, 176.7W. >> 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. >> > >_____________________________________________________________________ > >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: "David A. Nelson" Subject: Re: Monster Quake Date: Wed, 15 Oct 1997 00:01:07 +1200 Here's the CMT from CALTECH Dave Subject: CMT Mw=7.7 FIJI ISLANDS REGION General region : FIJI ISLANDS REGION surface waves (3.0,3.5,7,7.5 mHz) Stations used : COR KEV KIP NWAO SNZO TUC Origin time: 1997 287 9 53 18 Original location (lat,lon,depth) : -22.0000 -176.900 166 Moment tensor (x1.e26 dyncm) : Mrr : -11.017150 Mtt : 9.056068 Mff : 1.961082 Mrt : -9.261573 Mrf : -37.574108 Mtf : 14.807621 T-axis: moment= 42.549 plunge= 34.189 azimuth= 123.744 N-axis: moment= 0.235 plunge= 19.560 azimuth= 19.776 P-axis: moment= -42.784 plunge= 49.148 azimuth= 265.517 best double couple: Mo= 42.667(x1.e26 dyncm) Mw=7.7 tau= 19.4 nodal planes (strike/dip/slip): 16.95/ 82.10/-109.76 266.00/ 21.22/-22.33 Centroid location : -21.737 -176.628 170.152 Centroid time : 17.691 Variance reduction (%) : 78 *********** **** o**** *** oooooooooooo---*** ** ooooo oooooo--** ** ooo oo----oooo** * ooo o--------ooo* * oo o----------oo* **o oo-----------o** *o o-------------o* **o oo--------------** ** P + o---------------** ** oo---------------** * oo----------------* ** o----------------** * oo---------T------* * oo----------------* ** o---------------** ** o---------------** *** oo------------*** ****oo---------**** *********** 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: "James M Hannon" Subject: Thermal Accelerometers Date: Tue, 14 Oct 1997 10:40:41 -0500 I saw a Humphrey Inc. add in Sensors magazine. They descirbe a thermal accelerometer based an heat transfer no moving parts or fluids. Does anyone know how this works? Jim Hannon _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Erich F. Kern" Subject: Re: Thermal Accelerometers Date: Tue, 14 Oct 1997 09:07:46 -0700 Hi Jim, Thermal sensor elements within the sealed package detect changes in convection currents due to acceleration. Charles Patton and I have been working on a 2 axis seismograph using the Humphrey device. Its noise floor is 2 orders of magnitude lower than the analog devices ADXL05, but probably not low enough to detect teleseismic events. Freq. response goes to D.C., so it makes a very sensitive tilt detector as well. Humphrey's 4 page data sheet can be downloaded from our web page. See the address below. Regards, Erich *************************************************************** Please visit our web site at: http://www.dconn.com/FatQuartersSoftware Thank you *************************************************************** ---------- > From: James M Hannon > To: PSN-L@............. > Subject: Thermal Accelerometers > Date: Tuesday, October 14, 1997 08:40 > > > > > > I saw a Humphrey Inc. add in Sensors magazine. They descirbe a thermal > accelerometer based an heat transfer no moving parts or fluids. Does > anyone know how this works? > > > Jim Hannon > > > > _____________________________________________________________________ > > 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: "Charles R. Patton" Subject: Re: Thermal Accelerometers Date: Tue, 14 Oct 1997 09:29:23 -0700 This is the same sensor Erich Kern and I used in the experimenter article I did for the Geo-Monitor which ended up with about a 30 uG p-p noise floor and thus a continuous full range of +- 15 ug to +- 2 g. Go to: http://patent.womplex.ibm.com and look up: 5581034 : Convective accelerometer and inclinometer ABSTRACT: A convective accelerometer and inclinometer includes two temperature sensing elements mounted within a sealed enclosure containing a gas. The application of heat to the gas within the enclosure by a heating element causes the gas to flow in a predetermined pattern in free convection. When linear acceleration or inclination is applied to the enclosure the convective flow of gas is affected causing a temperature differential between the temperature sensing elements. This temperature differential is measured as a difference in electrical resistance between the two temperature sensing elements which is proportional to the acceleration. The device can be used to measure linear acceleration, velocity, position or inclination. The device can also be used as an inclinometer for measuring the angle of gravity. The device has a wide variety applications particularly within the automotive field. If you want more, you can click on the "View Images" icon and get the whole thing. Charles R. Patton patton@......... James M Hannon wrote: > I saw a Humphrey Inc. add in Sensors magazine. They descirbe a thermal > accelerometer based an heat transfer no moving parts or fluids. Does > anyone know how this works? > > Jim Hannon _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: prewar Subject: 3D and earth partical direction Date: Tue, 14 Oct 1997 18:30:01 +0100 Jim Hannon wrote: > I would be very interested in hearing more about how you plan on viewing > the 3d data. I am working on a 3 axis instrument with each axis having > identical response. But I haven't any good ideas on viewing the data. > Hi Jim again, Further to my suggestions, in answer to the above...... It occured to me that you may like to show your 3 dimensional o/p's in the following manner. It would be a show for family, friends and the local science museums, to show youngsters what the moving earth beneath their feet, REALLY looks like. First, let us suppose that when you are viewing your monitor, that you are facing NORTH. If you can program, write in the following patch as item 9 on my previous selection list. If you cannot program PC's, I see from the archives, (yes, I'm still struggling to read through them ALL!), that there are many folk in your part of the world on the PSN, who can program PC,s. Draw a circle or ball on screen ( this is representative of an earth partical), whose DIAMETER is directly controlled by the A/D o/p from the N/S seismo. It's vertical position on the screen is controlled by the A/D o/p from the VERT seismo, and whose lateral position on the screen is controlled by the A/D o/p from the E/W seismo. Program to hold all coordinates in 3 variables, and ERASE circle or ball at end of each A/D conversion. Then simply redraw at new positions, and new diameter at next set of coordinates, given by all 3 new A/D conversions. Repeat this process until the wife asks, 'When are you going to pack up watching that VDU?' . ALSO, as the circle or ball grows smaller ,(earth particals moving to the NORTH), program to slowly increase the BLUE o/p on the redraw colour. Conversly, as ball/circle grows larger,(earth particals moving to the SOUTH), program to increase the RED o/p on the redraw colour. I suggest these particular colours, because as things receed they become lost in a BLUE mist, and as they approach, they become brighter, and more potent looking. So RED. If your monitor faces, say, EAST, then VERT seismo still controls vert position on screen. BUT this time, of course, the ball/circle DIAMETER/COLOUR is controlled by the A/D o/p from the E/W seismo, (ball getting smaller on earth movement to the EAST, and larger to the WEST) . The N/S seiemo now controlling the lateral position on the ball/circle.......and so on. If you wish to lay in bed with monitor up on the ceiling, then the diameter of the ball/circle will be controlled by the VERT seismo...well it takes all sorts I Hope that all above is clear......please give us a shout if not. Now, comes the real 'party piece'......... Replay all those great tremors which you hold on Hard Disc, taken from your 3 dimensional seismos, at x2, x10, x100 normal speed, or anything you wish. Now watch the youngsters eyes as the 'ball' wizzes around, as a TRUE replay of how the earth REALLY moved, on the day that the ornament fell of the shelf . Also program for TWO balls/circles to compare various 'events' with each other, from two earthquake files together on HD. NONE of the programming above is too difficult, but the results may be worth watching.....I bet you can't wait to get all of your 3D seismos up and running now, Jim........don't forget that ALL 3 seismos must be calibrated for equal volts out for equal movement, but I believe that you are doing this. Yes, Barry as you say, direction may be seen with 3D, certainly for NEAR events. Just watch the coloured ball ,and it will show you!!! Regards, Albert Noble. (England) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: prewar Subject: APOLOGY Date: Tue, 14 Oct 1997 19:12:48 +0100 Hello all, Have just read letters about your large earthquake. In view of this, my remarks about falling ornament off shelf, in my letter to Jim an hour ago, was in very bad taste, and I apologise for making it. Regards...Albert Noble. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: lahr@................. (Dr. John Lahr (USGS-GI Seismologist)) Subject: 3D Date: Tue, 14 Oct 1997 10:38:35 -0800 Albert, Another way to get the in-and-out direction would be with 3D colored glasses. Each ball would be drawn twice, once in red and once in blue. Use zero seperation for the circles when the ball is in the plane of the screen and increase the separation linearly one way for into the screen locations and the other way for out of the screen location. Viewed with 3D glasses the ball will appear to move in and out of the screen as well as laterally. I wrote a program in the DOS-Turbo Pascall-days that would display a rotating wire frame figure this way and it worked well. JCLahr ################################## John C. Lahr ################################# Seismologist ################################ U.S. Geological Survey ############################### c/o Geophysical Institute ############################## 903 Koyukuk Drive ~~~~~~~~~~~~~~ Get ~~~~~~~~~~ ############################# ########################################################### P.O. Box 757320 ################################ Fairbanks, AK 99775 ################################# Phone: (907) 474-7997 ################################## Fax: (907) 474-5618 ~~~~~~~~ the thrust? ~~~~~~~~~~~~~~ lahr@........ #################################### http://www.aeic.alaska.edu/Input/lahr/ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: lahr@................. (Dr. John Lahr (USGS-GI Seismologist)) Subject: Re: THREE DIMENSIONAL Seismograghs and software. Date: Tue, 14 Oct 1997 12:40:47 -0800 Barry Lotz writes: "Hi All I haven't been following the Three Dimensional thread in detail but I think (in theory) if one has the three components of an arriving wave that it should be possible to determing the direction the wave is coming from by vector analysis. With the addition of the arrival times, one could "pinpoint" the epicenter from one station. In reality I think the waves from three directions could get pretty complicated for other than local events." This is a good technique for teleseismic events within about 90 degrees distance. If you think about the particle motion of the P-phase as being along the travel path between your station and the earthquake, then you can see, for example, that if the motion of the P-phase is up, south, west, then the earthquake came from the northeast. If the motion is down, north, west, then the earthquake came from the event came from the northwest. Up motion always points away from the source and down motion points toward the source. The first motion of the P-phase is the best part of the seismic signal to use this technique on, as the very first waves to arrive have come by a direct path. If you can identify the S phase, then the distance can be computed VERY roughly by (S - P - 2)*10 ~ distance in degrees. Measure the time between P and S in minutes, subtract 2 mintues, then multiply by 10 to get the distance in degrees. I put a travel-time table on my web site at: http://www.giseis.alaska.edu/Input/lahr/tttable.gif JCLahr ################################## John C. Lahr ################################# Seismologist ################################ U.S. Geological Survey ############################### c/o Geophysical Institute ############################## 903 Koyukuk Drive ~~~~~~~~~~~~~~ Get ~~~~~~~~~~ ############################# ########################################################### P.O. Box 757320 ################################ Fairbanks, AK 99775 ################################# Phone: (907) 474-7997 ################################## Fax: (907) 474-5618 ~~~~~~~~ the thrust? ~~~~~~~~~~~~~~ lahr@........ #################################### http://www.aeic.alaska.edu/Input/lahr/ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Stephen Caruso Subject: Re: Thermal Accelerometers Date: Tue, 14 Oct 1997 18:51:56 -0400 (EDT) Check out ELECTRONICS NOW recent issue on thermal wind speed measure? STEPHEN CARUSO CET KB8UGH _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "David A. Nelson" Subject: Re: Seismograghs and software. Date: Wed, 15 Oct 1997 11:48:31 +1200 John, just been playing with the phase arrival time setup on your pages interesting.... there must be some differences in you calc. methods to what Larry uses in Winquake. eg. here is the data from your calc. DATE-(UTC)-TIME LAT LON DEPTH MAG Q COMMENTS 97/10/14 09:53:18 21.95S 176.92W 166.2 6.5Mb A FIJI ISLANDS REGION delta azimuth (degrees clockwise from north) (deg) eq-to-station station-to-eq 25.92 200.4 27.6 travel arrival time # code time(s) dy hr mn sec 1 P 316.61 0 9 58 34 2 P 320.80 0 9 58 38 3 S 575.14 0 10 2 53 4 PKiKP 980.06 0 10 9 38 Questions there are two "P" times ? you have delta deg and station to eq deg what is the difference ? Now the distance calc. by WQ for the distance between me and the epic. is is 2886 km or 25.95 deg (which is your delta deg. measurement). TNX 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: Seismographs and software. Date: Tue, 14 Oct 1997 16:20:22 -0700 At 11:48 AM 10/15/97 +1200, Dave Nelson wrote: Please note that there is a bug in some of the newer releases of WinQuake around the azimuth calculation in the Great Circle Distance calculator dialog box. If you have a new version of WQ, I not sure exactly what version this bug started showing up in, with the GC dialog box that has both the azimuth to and from the event, then you should not rely on the azimuth numbers. One of them is bogus. I have a beta release ready that has this bug fixed. It also has two new features that some may find useful. I'm going to be announcing the new release later tonight. -Larry Cochrane Redwood City, PSN >John, > just been playing with the phase arrival time setup on your pages > interesting.... there must be some differences in you calc. methods to >what Larry uses in Winquake. > >eg. here is the data from your calc. > > DATE-(UTC)-TIME LAT LON DEPTH MAG Q COMMENTS > 97/10/14 09:53:18 21.95S 176.92W 166.2 6.5Mb A FIJI ISLANDS REGION > > delta azimuth (degrees clockwise from north) > (deg) eq-to-station station-to-eq > 25.92 200.4 27.6 > > travel arrival time > # code time(s) dy hr mn sec > 1 P 316.61 0 9 58 34 > 2 P 320.80 0 9 58 38 > 3 S 575.14 0 10 2 53 > 4 PKiKP 980.06 0 10 9 38 > > Questions there are two "P" times ? > you have delta deg and station to eq deg what is >the difference ? > > Now the distance calc. by WQ for the distance between me and the epic. is > is 2886 km or 25.95 deg (which is your delta deg. measurement). > >TNX >Dave > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: New event? Date: Tue, 14 Oct 1997 07:33:06 -0700 Hi all Is another event coming in? @ 10/15/97 01:03:40 UTC??? Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "David A. Nelson" Subject: Re: New event? Date: Wed, 15 Oct 1997 14:42:47 +1200 yes there is Barry I recorded it here in NZ Dave At 07:33 AM 10/14/97 -0700, you wrote: >Hi all > Is another event coming in? @ 10/15/97 01:03:40 UTC??? > Barry > >_____________________________________________________________________ > >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: "David A. Nelson" Subject: yet another large event Date: Wed, 15 Oct 1997 17:21:41 +1200 Aleutians this time Dave Subject: CMT Mw=6.3 ANDREANOF ISLANDS, ALEUTIAN IS. General region : ANDREANOF ISLANDS, ALEUTIAN IS. surface waves (3.0,3.5,7,7.5 mHz) Stations used : COR KBS KEV NWAO TATO TUC Origin time: 1997 288 3 11 11 Original location (lat,lon,depth) : 51.3000 -177.700 31 Moment tensor (x1.e26 dyncm) : Mrr : 0.497063 Mtt : -0.184046 Mff : -0.313017 Mrt : -0.063278 Mrf : -0.005620 Mtf : 0.002294 T-axis: moment= 0.503 plunge= 84.720 azimuth= 175.564 N-axis: moment= -0.190 plunge= 5.269 azimuth= 359.174 P-axis: moment= -0.313 plunge= 0.331 azimuth= 269.144 best double couple: Mo= 0.408(x1.e26 dyncm) Mw=6.3 tau= 4.1 nodal planes (strike/dip/slip): 353.87/ 44.91/ 82.53 184.36/ 45.57/ 97.39 Centroid location : 51.319 -178.244 72.095 Centroid time : 20.920 Variance reduction (%) : 1 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: "David A. Nelson" Subject: yet another large event Date: Wed, 15 Oct 1997 17:32:17 +1200 Aleutians this time Dave Subject: CMT Mw=6.3 ANDREANOF ISLANDS, ALEUTIAN IS. General region : ANDREANOF ISLANDS, ALEUTIAN IS. surface waves (3.0,3.5,7,7.5 mHz) Stations used : COR KBS KEV NWAO TATO TUC Origin time: 1997 288 3 11 11 Original location (lat,lon,depth) : 51.3000 -177.700 31 Moment tensor (x1.e26 dyncm) : Mrr : 0.497063 Mtt : -0.184046 Mff : -0.313017 Mrt : -0.063278 Mrf : -0.005620 Mtf : 0.002294 T-axis: moment= 0.503 plunge= 84.720 azimuth= 175.564 N-axis: moment= -0.190 plunge= 5.269 azimuth= 359.174 P-axis: moment= -0.313 plunge= 0.331 azimuth= 269.144 best double couple: Mo= 0.408(x1.e26 dyncm) Mw=6.3 tau= 4.1 nodal planes (strike/dip/slip): 353.87/ 44.91/ 82.53 184.36/ 45.57/ 97.39 Centroid location : 51.319 -178.244 72.095 Centroid time : 20.920 Variance reduction (%) : 1 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: New beta release of WinQuake and SDR. Date: Tue, 14 Oct 1997 22:04:27 -0700 Greetings, I just got finished with the next release of WinQuake, version 2.5, and would like some beta testers to try it out. I also have a new beta release of SDR, version 2.4, that goes along with the WQ release. The WinQuake release has two new features and some bug fixes. The two bug fixes are: The Great Circle Distance Calculate dialog box was displaying bogus numbers for the azimuth calculation. Thanks to Robert Barns for reporting this bug. The second bug was around the Data Integration feature. On 16 bit versions it would crash on some event files. Thanks to Bob Lewis for reporting this one. The two new features are both network related. If you are going to try this release please save this email message. Its the only documentation I have for the new features. The first feature allows the user to directly access report information over the Internet. It uses the UNIX finger service (TCP/IP port 79) to get report information directly from the source. This report information has event information (location, time of origin etc) that can be used to update event files. Before you had to use some other method to get the report into a file local to the system and then have WinQuake read it in. With this new feature all you have to do is select the finger server/host in a dialog box and WinQuake will retrieve the information directly over the Internet. It save the report/finger information in a file and then parse out the event information and displays it in a list box. The report information can then be used to fill in the header information of an event file or used in the second new feature below. There's one big problem... This feature is only supported in the 32 bit version. For WinQuake to access information over the Net it needs to have access to sockets. The sockets under Win95 and NT are easier to deal with. Since the 16 bit version of Windows is now obsolete I'm not going to spend anytime supporting it. Sorry... To use this feature all you need to do is go to the Report dialog box. You can use the Report tool bar icon or the File / Report menu item to open this dialog box. There you will see a new button called "Load Network Report". This button is grayed-out in the 16 bit version. After selecting this button you will see a new dialog box. If you have the NETWORK.DAT file in the same directory as WQ you should a list of finger commands/host names in the list box. If you double click (or use the "Connect" button) on one, WQ should attempt to connect to the finger server and download the file. Obviously you will need to be logged onto the net to get any data back. If everything works as planed the dialog box will close up when it finishes collecting the data. The Report dialog report list should now have the new event information in it. If there are any errors, the Network dialog box will stay open and an error message should show up in the Status line. The "Directory" button sets the default location for the report files that are created using this feature. The actual name of the report file is based on the host name. I replace all of the "." in the host name with a "_" and then tag on the end ".rpt". This file is then saved using the directory specified by this button. The Add, Del and Save buttons are used to manage the NETWORK.DAT file. This file holds the information needed for the feature to work. This file must be located in the same directory as the WQ exe file. You also need the REPORT.DAT file. This file has the parsing information use to extract the event information. It also needs to be in the same dir. as the WQ exe file. Both DAT files are in the beta zip file. In the future WinQuake will be able to get other information using direct connection to the Internet. This could be event files or other report information that is not available as a finger service. I would like to get the norcal.list file directly using http. This file has all of the local events, even the ones smaller then the 2.0 cutoff of the quake@.............. list. This list is available using http and maybe ftp. What I need to do is figure out the protocol of both so I can have WQ use these protocols to download data/files. The second new feature is only for SDR users. It is supported in both the 16 and 32 bit versions. This feature allows the user to request/replay an event file using WinQuake. To use this feature you must have your SDR and main Windows system (Win3.1, Win95 or NT) networked together using two NIC cards. Many of the sdr users have there systems networked so I thought I would add this feature. It uses the same SDR feature used to implement the request data form at http://psn.quake.net/request.html. This form allows the user to extract a PSN formatted event file from my SDR systems based on a start time, number of minutes to save, channel etc. SDR then uses this info and creates an event file. Its similar to doing a replay, but remotely. Setting things up to get this feature working is a little complicated so here it goes... First you need to get the two systems networked together. I would suggest loading Win95 on both systems if you are going to try doing this. In the beta release of SDR there is a netwin95.txt file that explains how to do this. Another file you need too read is sdrwin95.txt. This file explains how to run SDR in the DOS only mode of Win95. If you get the network stuff working you should be able to map a drive letter, say "D:" on your SDR system so that it is the same drive as the "C:" (or other local disk) drive on your Windows system. Another words, if you have a dir/path called c:\sdr\event\ on your Windows system, and, if you have your sdr system maps the D: drive to be the same as the C: drive on the other system, then, d:\sdr\event\ will be the same directory, and, files can be shared between the two systems. For this feature to work you will need two directories. One will hold the temporary request information file that SDR reads for the replay information, and the other will hold the returned event file. Create two directories like c:\sdr\event and c:\sdr\request on your Windows system. Now enter the shared drive and path information in the field "Request Control File Path" under the F5 settings in SDR. If the SDR D: drive = the C: drive on the Windows system then enter "d:\sdr\request\" for that menu item. That's all you need to do the SDR side of things. SDR will look for a request file in that dir. every 10 seconds. If it finds one, it tries to do the replay and create the event file. For more information on how the request process works in SDR, please read the request.txt file that comes with the beta release of SDR. Now for WinQuake. When WQ firsts starts up it looks for a file called REPLAY.DAT in the same dir. as WQ runs out of. If it finds it, then the new "Replay" button in the File Open dialog box will be enabled. If the file is not there this button will be disabled. Since this button will be disabled when you run the new WQ for the same time you will have to use the menu item called "Replay Setup" under the File menu items. This dialog box is used to create and manage the REPLAY.DAT file. The first item in this dialog box is the returned event file path that SDR will use to place files in. Use the "Change" button to select the directory that you will be using, like c:\src\event, to hold the returned event files in. Next you need to add the channel information for each of your sensors you are running. For each channel select the "Add" button. In the Add Replay info dialog box add the File extension for that channel, like LC1. If you only have one sdr system keep the SDR system number at 1. For the Control File directory use the "Change" button and select the dir. you will be using for the request control file, like c:\sdr\request. After entering the replay info you should be able to do a replay. The Replay button should now be enabled in the File Open dialog box. In the Replay dialog box you will see a series of edit boxes for the start time, save length, channel etc. After filling in the start time and channel press the "Replay" button. WQ will create a request file for SDR to read and then waits for the event file to be created by SDR. If after ~40 seconds there is no event file found, WQ will time out. If it does find the event file it will close out the Replay dialog box and open the event file. The "Report" and "Report Time" can be used to set the starting time based on the currently selected report time. The Save Default check box is used to save selected fields, marked with a * in the group box name, as default settings for the next time you run WQ. The SDR beta release as only minor changes in it. While you do not need to upgrade to it for the second WQ feature to work, it would be best if you do. This version as some changes around how SDR handles request file errors. Thats it! The beta release for both the 16 and 32 bit version of WinQuake and SDR can be download using the following URL's. 32 bit WinQuake: ftp://ftp.seismicnet.com/users/psn/software/wq32b1.zip or ftp://psn.quake.net/software/wq32b1.zip 16 bit WinQuake: ftp://ftp.seismicnet.com/users/psn/software/wq16b1.zip or ftp://psn.quake.net/software/wq16b1.zip SDR: ftp://ftp.seismicnet.com/users/psn/software/sdr24b.zip or ftp://psn.quake.net/software/sdr24b.zip Please use the ftp.seismicnet.com address if possible. This system is on a higher speed link into the Internet then my 28.8k modem at psn.quake.net. The WinQuake zip files only contain the new exe and some dat files. After unzipping the file all you need to do is copy the files over to your working WinQuake directory. Make sure you stop the old version before doing the copy. For the SDR release there is a new exe file and all of the current text files I have for documentation. All you need to do is copy the sdr.exe file over to your SDR system and restart it. If you run into any problems, of have suggestions on the new features (or old ones) please let me know. Thats it, enjoy! -Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: frankcnd@.......... (Frank Condon) Subject: Fontana, CA Trend 4.0 Date: Wed, 15 Oct 1997 01:06:09 -0700 (PDT) Hi All! There was a 4.0 in Fontana, CA that occurred at 3:31 PM PDT. Maybe the erratic readings on my equipment that I noted here just a few days ago was a precursor to it. I monitor the range of 0.1 to 3.0 Hz for any changes in signal amplitude and noticed quite an erratic amplitude shift in the last week before the 4.0. The monitoring location is within five miles of the epicenter. I figured that I was seeing some kind of event brewing on the San Jacinto Fault. I was monitoring and noting some drastic changes in the geo-magnetic field strength of the area, too. I noted my last drastic change in signal level at approximately 3 PM PDT, only 30 minutes before the earthquake happened. Did anyone else in this area get any strange readings prior to this event? I'd be interested in sharing notes with you if possible. Oh, and BTW what ever happened to the predicted Parkfield event? Send mail to: frankcnd@.......... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: prewar Subject: Re: 3D displays and holograms etc. Date: Wed, 15 Oct 1997 11:56:39 +0100 Dr. John Lahr (USGS-GI Seismologist) wrote: > Albert, > > Another way to get the in-and-out direction would be with > 3D colored glasses. Each ball would be drawn twice, once > in red and once in blue. Use zero seperation for the circles > when the ball is in the plane of the screen and increase the > separation linearly one way for into the screen locations and > the other way for out of the screen location. Viewed with 3D > glasses the ball will appear to move in and out of the screen > as well as laterally. > > I wrote a program in the DOS-Turbo Pascall-days that would > display a rotating wire frame figure this way and it worked > well. > > JCLahr Hello John, Thanks for your comments re 3D moving earth partical display. (I think I must shorten this to MEP .) Yes, your red and blue balls + glasses, would be VERY impressive. I have great concern over here, that youngsters are not being exposed to enough science. You may know that our Prof. Richard Dawkins (author of, ' The selfish gene etc.) , now holds a chair at Oxford, solely to promote the advancement of science, among the general population. Now, seismic drum recordings , and PC analysis are fine for those in the know, but it doesn't SHOW youngsters, (or me!!), what is really going on, 'down there', as if we were really PRESENT in the bowels of the earth, does it? As a professional seismologist, you are no doubt be more aware of this, than I. I can visualise, in a science or geological museum, this 3D display, showing EXACTLY how the earth particals move during an earthquake......it may not be scientific, but it would encourage more to take an interest in what is beneath their feet . What do you think about this? Earthquakes from the past could be easily 'replayed', at x2, x10 ,x100, etc. speeds, as well as in real time, to demonstrate how the P, S, Love and Rayleigh waves etc. arrive. Near events would certainly be of interest, the 'earth partical ball', oscillating as it would, with a bias towards the 'event' direction. Any pile driving, or underground trains passing in town would look very good as well , don't you think? "Oh yes,", says a visitor to the museum, "there's a train passing from east to west, and there's the vibration from the new store going up on 52nd. street".....!!!!! Perhaps a hologram of the moving ball earth partical in the centre of an area, where one could walk AROUND IT, etc, would be the ultimate display....as I mentioned in my e-mail to Jim, this hologram display is certainly my aim................... .........DOES ANYONE OUT THERE USE PC CONTROLLED HOLOGRAMS, which could be adapted to show 3D moving earth partical displays, (MEP's ), using the o/p from 2 horizontal and one vertical seismograph??? Thanks for reply John...I would like to take this opportunity to thank all who have responded to my letters. It's a great help getting this knowledgable feedback, here in my village, where seismographic information is somewhat sparse!! Regards to you John, and all, Albert Noble (England). _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: lahr@................. (Dr. John Lahr (USGS-GI Seismologist)) Subject: Re: Seismograghs and software. Date: Wed, 15 Oct 1997 10:55:21 -0800 > From dann@........ Tue Oct 14 15:49:35 1997 > > John, > just been playing with the phase arrival time setup on your pages > interesting.... there must be some differences in you calc. methods to > what Larry uses in Winquake. > > eg. here is the data from your calc. > > DATE-(UTC)-TIME LAT LON DEPTH MAG Q COMMENTS > 97/10/14 09:53:18 21.95S 176.92W 166.2 6.5Mb A FIJI ISLANDS REGION > > delta azimuth (degrees clockwise from north) > (deg) eq-to-station station-to-eq > 25.92 200.4 27.6 > > travel arrival time > # code time(s) dy hr mn sec > 1 P 316.61 0 9 58 34 > 2 P 320.80 0 9 58 38 > 3 S 575.14 0 10 2 53 > 4 PKiKP 980.06 0 10 9 38 > > Questions there are two "P" times ? > you have delta deg and station to eq deg what is > the difference ? > > Now the distance calc. by WQ for the distance between me and the epic. is > is 2886 km or 25.95 deg (which is your delta deg. measurement). > > TNX > Dave Dave, The eq-to-station and station-to-eq numbers refer to the azimuth from the earthquake to the station and visa versa. The difference between 25.95 and 25.92 must be in the distance algorithms used. The travel time software I'm using is from NEIC and it reports phases whenever there is an arrival, according to the crustal model, rather than just the first arrival of a type. The two P phases are for rays that "bottom out" at different depths. JCLahr ################################## John C. Lahr ################################# Seismologist ################################ U.S. Geological Survey ############################### c/o Geophysical Institute ############################## 903 Koyukuk Drive ~~~~~~~~~~~~~~ Get ~~~~~~~~~~ ############################# ########################################################### P.O. Box 757320 ################################ Fairbanks, AK 99775 ################################# Phone: (907) 474-7997 ################################## Fax: (907) 474-5618 ~~~~~~~~ the thrust? ~~~~~~~~~~~~~~ lahr@........ #################################### http://www.aeic.alaska.edu/Input/lahr/ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Martin Brewer Subject: RE: New Station on the USA map Date: Wed, 15 Oct 1997 17:38:38 -0300 Welcome Robert and hello again everyone else. Robert, did you or anyone else pick up one or more 'quakes with an = origin time around 10:08 UTC on 14 October? I recorded a very rich = trace about that time (peak amplitude 939) which appears to be a = magnitude Ms 6.6 at a distance of about 35 degrees (3,800 km) from = Bermuda. The only event I see listed by NEIC around that time is the = one in the Fiji Islands region with origin time 09:53:18 and magnitude = Mb 6.5 But it can't be that one as the event was 119 degrees from = Bermuda. It could be a series of much smaller local events in the North = Atlantic? Be glad of any feedback, Martin -----Original Message----- Hi all, Please welcome Robert Laney from Herndon, Va, to the group. = =20 It's good to see another east coast seismic station up and running, = look for him on the USA map on my pages. Dave From: Edward Cranswick Subject: Itailian M5 Tuesdy 14 Oct Earthquake: Reports/Recordings? Date: Wed, 15 Oct 1997 15:31:06 -0600 PSN- I am sitting here with Paolo De Martini who has asked me whether there is anyt PSN information about the M5 earthquake that took place yesterday in the same location as the earthquakes of 26 Sep. Paolo is a paleoseismologist working at the National Istitute of Geophisics in Rome and he is interested in this last aftershock that is not so small considering the elapsed time with respect the main one! -Paolo Marco De Martini -- 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: Robert L Barns <75612.2635@..............> Subject: Three Dimensional Seismograph, thoughts, and a poem! Date: Wed, 15 Oct 1997 20:48:12 -0400 Prewar, Re:heaters for seismometer enclosures. I described my enclosure-heater= system for a Lehman rather fully in e-mail to the list on 10/29/96. You can look at this by going to psn.quake.net, then to "Archives of Past PSN-L messages". Then download the 4th quarter of '96 (psnl96q4.zip, 114k). After unzipping, search for "styrafoam". Yes, I'm sure that the heater should be placed at the center of the top= of the enclosure. This will stagnate the air in the box and prevent convection currents. My heater is a 5 ohm resistor supplied with 9V AC a= nd thus dissapates 16 watts. This produces a gradient of about 8 deg F from= top to bottom (hotter at the top, of course). Of course, the size of the= gradient with 16 watts will depend upon the quality of the insulation. T= he 2" thick styrafoam I have is highly insulating. This thing is in my basement where the temp. over the whole year is in the range from 60 to 7= 5 deg F. I'm guessing that even in a less stable place, this much insulati= on will give good performance. I now have an additional 1 year of experience with this arrangement and= I'm still very happy with it. You can make a thermometer for probing the inside of the box from eithe= r a Si diode or a Si transistor. For the transistor, make it into a diode = by shorting the base to the collector. If these are small( e.g. 2N2222), th= ey will have fast response. With either of these, measure the forward volta= ge drop across the device in series with a relatively high resistor. I used= 22,000 ohms in series with a 9V battery. Use a digital voltmeter. The forward voltage drop is very linear with temperature and the slope is -2.= 2 millivolts/deg C. Of course, you will have to calibrate each unit by measuring the voltage at a known temperature. = = Best of luck with your rig. Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Surface wave amplitude Date: Wed, 15 Oct 1997 07:25:27 -0700 Hi All I have been getting teleseismic events with small P & S amplitudes and large surface amplitudes. Recently I have been getting the opposite ie. large P & S amplitudes and little or no surface waves. I suspect it has to do with the depth of the event and the direction of the station orentation with respect to the orentation of the event. Any thoughts?? Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "David A. Nelson" Subject: Re: Surface wave amplitude Date: Thu, 16 Oct 1997 15:16:51 +1200 Barry, yes, depth and orientation do both have an effect on the resulting seismogram. it is also interesting to note that NOT all large shallow events are rich in surface waves, some do, some don't, on the other hand over the many years I have seen several moderate events (5.5 - 6.3) that have very strong surface waves. one in particular was in the late '80's, a Mb6.2 in the Bay of Plenty, Nth Is. NZ, the P and S amplitudes were "normal" for that sized event at its distance from me but the surface waves went on and on and on. Talking to the Seis. Obs. professionals at the time, they suggested that it was a very shallow event and a very long fault rupture. A feature I also notice here in Dunedin, NZ, is that quakes over 2500km ( ie. the Santa Cruz. Is., Fiji, Tonga regions) usually have a much larger P wave ampl. than the S wave. on a horizontal seismometer. there may/may not be some surface waves depending on the quake depth. Dave At 07:25 AM 10/15/97 -0700, you wrote: >Hi All > I have been getting teleseismic events with small P & S amplitudes >and large surface amplitudes. Recently I have been getting the opposite >ie. large P & S amplitudes and little or no surface waves. I suspect it >has to do with the depth of the event and the direction of the station >orentation with respect to the orentation of the event. Any thoughts?? > Barry 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: "Ryan A. Meyer" Subject: novice to this hobby Date: Fri, 17 Oct 1997 01:19:09 -0400 X-Priority: 3 (Normal) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Tjis is very interesting stuff!! I am presently building the mechanic part of a Lehman seismograph...using the plans that were published years ago...Is there a better electronic amp to build than the one shown in the magizine? More gain and/or less noise? I'm certain that over the years and with all the electronic wizards out there, there's no sense in trying to re-invent the wheel.... Any comments will be appreciated, please e-mail them to me at: dmeyer@.............. thanks!! JIM WT2W _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: prewar Subject: Re: seisvole and seismic waves Date: Thu, 16 Oct 1997 17:45:15 +0100 Dr. John Lahr (USGS-GI Seismologist) wrote: > Albert, > > Check out these two programs, which I think are excellent for > education. You may have seen this posting, but I'm not sure when > you joined the psn listserver. > JCLahr > > > From lahr@................. Sat Oct 4 11:24:22 1997 > > Date: Sat, 4 Oct 1997 11:33:48 -0800 > > From: lahr@................. (Dr. John Lahr (USGS-GI Seismologist)) > > To: psn-l@.............. > > Subject: Re: Image maps - seisvole - seismic > > Cc: lahr@................. > > > > > There are far too many features to describe in detail here. For > > more information on Seismic, check out Alan Jones' home page at: > > http://sunquakes.geol.binghamton.edu/faculty/jones/ > > > > http://www.aeic.alaska.edu/Input/lahr/ > > Hello John, Thanks...have started looking at these web pages, very good and most helpful to me.........somewhat more up to date than the seismo books which I have. What with these, and the archives, I shall be burning the midnight oil for many nights to come!! Regards, Albert Noble (England) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: Seismograghs and software. Date: Thu, 16 Oct 1997 15:37:03 -0700 At 10:55 AM 10/15/97 -0800, John Lahr wrote: >Dave, > >The eq-to-station and station-to-eq numbers refer to the azimuth from >the earthquake to the station and visa versa. The difference between >25.95 and 25.92 must be in the distance algorithms used. That works out to be about 3km difference... 1 deg = ~111.17km so 111.17 * ..03 = 3.33km -Larry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Martin Brewer Subject: Fiji event - Bermuda Date: Thu, 16 Oct 1997 20:44:22 -0300 Dave, I tried to send you two files(N-s and E-W) of the event I recorded at = the time the Fiji region 'quake occurred. I tried to send it by e-mail = from your home page but I got a message from the internet server = administrator that it couldn't be sent. As you know my C-drive got = wiped out recently. Please send me your e-mail address that I can use = from here. I apologise to all the other users for cluttering up the list with this = private message. Martin From: James Subject: From the "Drudge Report" Date: Thu, 16 Oct 1997 22:33:54 -0500 (CDT) Hello, I just had to pass this on. Found this in the Drudge Report http://www.drudgereport.com/ FRIDAY ENDING... Seismologists remain baffled by the continuing tremors in Italy. More than 2,000 events, six of them measuring more than four on the Richter scale, have hit central Italy over the past 20 days. Many DRUDGE REPORT readers in Italy have e-mailed in with dramatic details of life during the swarms. But now the LONDON TIMES runs a report in Friday editions that takes it all the way: rumors are spreading throughout Italy that "the Big One" is set to strike within the next 24 hours, in accordance with the prophecies of Nostradamus. The TIMES' Rich Owen filing from Rome: "For many superstitious and increasingly nervous Italians, the quakes reveal 'the hand of God' or at least of fate. 'An earthquake obsession without end' was the headline in yesterday's LA STAMPA, which reported that people near the epicenter were 'awaiting the end of the world...' "Bookshops in Rome and Perugia have sold out of the prophecies of Nostradamus, who is said to have predicted that the end of the world would be presaged by quakes "on three Fridays in a row". Many Italians believe Nostradamus predicted a third, apocalyptic earthquake today. Psychologists said pre-millennial fears were becoming widespread." _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: Surface wave amplitude Date: Thu, 16 Oct 1997 19:48:26 -0700 The 6.8Ms Chile event a few days ago was a strange one... It is listed as a shallow event (33km deep) but it produced very small surface wave amplitudes. The P and S where very large compared to the surface waves. Before the NEIC reported it I thought it was a deep event. Oh well..... -Larry Cochrane Redwood City, PSN At 03:16 PM 10/16/97 +1200, Dave Nelson wrote: >Barry, > yes, depth and orientation do both have an effect on the >resulting seismogram. it is also interesting to note that NOT all large >shallow events are rich in surface waves, some do, some don't, on the >other hand over the many years I have seen several moderate events (5.5 - >6.3) that have very strong surface waves. one in particular was in the >late '80's, a Mb6.2 in the Bay of Plenty, Nth Is. NZ, the P and S >amplitudes were "normal" for that sized event at its distance from me but >the surface waves went on and on and on. > Talking to the Seis. Obs. professionals at the time, they suggested that >it was a very shallow event and a very long fault rupture. > > A feature I also notice here in Dunedin, NZ, is that quakes over 2500km >( ie. the Santa Cruz. Is., Fiji, Tonga regions) usually have a much larger >P wave ampl. than the S wave. on a horizontal seismometer. there may/may >not be some surface waves depending on the quake depth. >Dave _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: Temperature control Date: Fri, 17 Oct 1997 09:59:11 -0400 Hi gang, There has been a lot of discussion recently about accurate temperature control of seismometer housings. I have no experimental evidence to cite on this question, just some thoughts based on general principals. If anyone has some directly applicable experience, I'm sure that we all would all like to here about it. At least for Lehman-type seismometers (used as velocity transducers in the usual fashion), I see no need for temperature control if the housing = is a good thermal insulator and a temperature gradient is established with t= he air at the top being a few degrees hotter than the bottom. This temperature gradient should greatly reduce convection currents in the air= around the seismometer. If the air temperature outside the housing chang= es so fast that the gradient is upset, air currents inside would give spurio= us signals but this seems very unlikely if ths insulation is good. I think that using a lamp at its rated voltage for the heat source is a= poor choice since the heat radiated by the lamp may heat different parts = of the sensor by different amounts. As the lamp is cycled on and off, this could introduce motion in the boom due to differential expansion of parts= of a Lehman (or an S-G). Heat transfer from resistors (which work at muc= h lower temperaure than a lamp filiament) will be predominantly by convecti= on and should cause much less differential expansion in parts of the Lehman.= A Lehman in its usual velocity sensitive mode is an AC device, that is,= its response does not extend to zero frequency. I think that this sez th= at its performance will be the same at 0 deg. and 100 deg. F. It seems possible that differential expansion of parts of a Lehman in this sort of= temperature range might change its period and/or the rest position of the= boom but I doubt that these changes would be significant. = Since a Shackleford-Gunderson operates part of the circuitry at DC, it might not be as immune to wide temperature swings. Maybe Larry can give = us his thoughts on this. Bob Barns = = _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: GeE777@....... Subject: Southern California Quakes Date: Fri, 17 Oct 1997 11:23:16 -0400 (EDT) During the last week, there have been many more than the normal numbers of events with less than 4.0 MAG. in Southern California. Is there a message here? George Erich GeE777@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Karl Cunningham Subject: Re: Southern California Quakes Date: Fri, 17 Oct 1997 08:38:53 -0700 One intesting thing is that there were three Southern California quakes in the 2's that all occurred within 2 minutes after the arrival of the P waves from the recent Fiji event. Hmmmmm. Karl Cunningham La Mesa, CA. PSN station #40 karlc@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Greg Lyzenga Subject: Re: Temperature control Date: Fri, 17 Oct 1997 08:55:57 -0700 >Hi gang, > There has been a lot of discussion recently about accurate temperature >control of seismometer housings. > I have no experimental evidence to cite on this question, just some >thoughts based on general principals. If anyone has some directly >applicable experience, I'm sure that we all would all like to here about >it. > At least for Lehman-type seismometers (used as velocity transducers in >the usual fashion), I see no need for temperature control if the housing is >a good thermal insulator and a temperature gradient is established with the >air at the top being a few degrees hotter than the bottom. ....(text deleted) >Bob Barns > I have similar opinions based on my experience. After a lot of only semi-successful experiments with heating the enclosure of my Lehman, I accidentally stumbled on what has turned out to be the most effective solution. In my experience, the most important factor has turned out to be brute force insulation. Lots of it. I had lined my box with the 2-inch variety of foil-backed foam building insulation, and it worked reasonably well with a little resistive top heating (~12 watts), although I still experienced some periods of convection during cold weather. Then I stumbled onto an improvement. It just so happened that our insulated spa cover was so badly weathered that it had to be replaced. However, being an incurable packrat, I couldn't bear to throw away two big sheets of 4-inch thick styrofoam, so I stashed them away in the garage. The only place I could find for them that was out of the way was wedged in the corner between the garage wall and my Lehman enclosure. Right away my thermal noise problems practically vanished! That extra few inches of foam did a lot more than I would have expected. So for me the moral of the story is insulate, insulate, insulate! - Greg _____ Gregory A. Lyzenga, Dept. of Physics, Harvey Mudd College lyzenga@................. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: lahr@................. (Dr. John Lahr (USGS-GI Seismologist)) Subject: Re: Surface wave amplitude of Chile Earthquake Date: Fri, 17 Oct 1997 08:40:38 -0800 Larry, Stu Sipkin's moment tensor solution for the Chile M6.8 quake of October 15 found a depth of 67 km. finger quake@................. still shows 33 km for the M6.8 but 47 km and 63 km for M5.4 aftershocks. Chances are the final solution for the main shock will have a depth in the 60's. JCLahr ***** Larry wrote: The 6.8Ms Chile event a few days ago was a strange one... It is listed as a shallow event (33km deep) but it produced very small surface wave amplitudes. The P and S where very large compared to the surface waves. Before the NEIC reported it I thought it was a deep event. Oh well..... -Larry Cochrane Redwood City, PSN ################################## John C. Lahr ################################# Seismologist ################################ U.S. Geological Survey ############################### c/o Geophysical Institute ############################## 903 Koyukuk Drive ~~~~~~~~~~~~~~ Get ~~~~~~~~~~ ############################# ########################################################### P.O. Box 757320 ################################ Fairbanks, AK 99775 ################################# Phone: (907) 474-7997 ################################## Fax: (907) 474-5618 ~~~~~~~~ the thrust? ~~~~~~~~~~~~~~ lahr@........ #################################### http://www.aeic.alaska.edu/Input/lahr/ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: [Fwd: Re: From Italy] Date: Fri, 17 Oct 1997 11:44:23 -0600 -- 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". Giovanni- That is a beautiful record. You should upload it to the PSN. The record appears to have less low-frequency content than it should from a seismometer with a period of 9 seconds. Paolo is now back in Rome, and I hope we, i.e., PSN, hear from him. -Edward Giovanni Rotta wrote: > > Hi Edward ! > I send you the file of the M5 earthquake of 14 October in Central Italy. > Have my best regards and a special greeting to Paolo from Italy. > Giovanni > > Giovanni Rotta > rottag@.......... > Via F. Pizzigoni, 10 > 33010 Resia (Udine) Italy > Lat. 46.22N Long. 13.18E > > --------------------------------------------------------------- > > Name: 971014l.gr1 > Type: unspecified type > Part 1.2 (application/octet-stream) > Encoding: base64 > Description: 971014l (GR1 File) -- 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". From: "Walter Williams" Subject: Chatsworth Quake Date: Fri, 17 Oct 1997 12:42:48 +0000 Hello All, Yesterday, (Oct. 16, 1997) around 09:00 (AM) PDT in the Chatsworth California, USA area (about 25 miles NW of Los Angeles), a 3.0m aftershock of the 1994 Northridge event was reported by local area news sources. My home is located in a neighbor area of Chatsworth. I was surprised when I did not see any posted comments in the PSN-L list both yesterday and today regarding this event? I fully expect the USGS instruments to sense these small events. But how many of the home-brew instruments created and maintained by members of the PSN were able to sense this event and how far away? Thank you. Best Regards Walt Williams, 97.10.17 dfheli@.............. Woodland Hills, California USA _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Greg Lyzenga Subject: Re: Chatsworth Quake Date: Fri, 17 Oct 1997 13:06:52 -0700 >Hello All, > >Yesterday, (Oct. 16, 1997) around 09:00 (AM) PDT in the Chatsworth >California, USA area (about 25 miles NW of Los Angeles), a 3.0m >aftershock of the 1994 Northridge event was reported by local area >news sources. My home is located in a neighbor area of Chatsworth. I >was surprised when I did not see any posted comments in the PSN-L >list both yesterday and today regarding this event? I fully expect >the USGS instruments to sense these small events. But how many of >the home-brew instruments created and maintained by members of the >PSN were able to sense this event and how far away? > I picked up the Chatsworth event just fine in Altadena, although it was not an especially remarkable event, particularly in light of some of the other bigger local events and teleseisms that have been coming in over the last few days. - Greg _____ Gregory A. Lyzenga, Dept. of Physics, Harvey Mudd College lyzenga@................. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Walter Williams" Subject: Re: Chatsworth Quake Date: Fri, 17 Oct 1997 15:27:30 +0000 Hello All, Actually the intent of my question was probably not too clear. Since this event was fairly small, I wondered at what large distance a small seismic event could be sensed using home-brew instruments in difference to 'professional' instruments. Could our friends in Italy sense a 3.0m event in Chatsworth should they happen to be using home-brew instruments? I infer the premise of this group is biased along amateur equipment usage. Thank you. Walt Williams, 97.10.17 dfheli@.............. Woodland Hills, California USA ------- Forwarded Message Follows ------- Date: Fri, 17 Oct 1997 13:06:52 -0700 From: Greg Lyzenga Subject: Re: Chatsworth Quake To: PSN-L Mailing List Reply-to: PSN-L Mailing List >Hello All, > >Yesterday, (Oct. 16, 1997) around 09:00 (AM) PDT in the Chatsworth >California, USA area (about 25 miles NW of Los Angeles), a 3.0m >aftershock of the 1994 Northridge event was reported by local area >news sources. My home is located in a neighbor area of Chatsworth. I >was surprised when I did not see any posted comments in the PSN-L >list both yesterday and today regarding this event? I fully expect >the USGS instruments to sense these small events. But how many of >the home-brew instruments created and maintained by members of the >PSN were able to sense this event and how far away? > I picked up the Chatsworth event just fine in Altadena, although it was not an especially remarkable event, particularly in light of some of the other bigger local events and teleseisms that have been coming in over the last few days. - Greg _____ Gregory A. Lyzenga, Dept. of Physics, Harvey Mudd College lyzenga@................. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: frankcnd@.......... (Frank Condon) Subject: Re: Southern California Quakes Date: Fri, 17 Oct 1997 17:24:47 -0700 (PDT) Hi George: The message is that we had better get our acts together, cause mother Earth is making some adjustments in the environment. Look at the swarm of small tremors in th Mammoth Lakes area over the last few weeks. Also, many weather changes are occurring with El Nino on the horizon! Another interesting fact is that there was a full blown Santa Ana wind condition during the time of the latest 4.0 magnitude earthquake and the temperatures were raised by about 20 degrees. Frank... >During the last week, there have been many more than the normal numbers of >events with less than 4.0 MAG. in Southern California. Is there a message >here? > >George Erich >GeE777@....... > >_____________________________________________________________________ > >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: Edward Cranswick Subject: Re: Chatsworth Quake Date: Fri, 17 Oct 1997 20:52:15 -0600 Walter- In general, the detection threshhold for earthquakes is as much a function of the noise characteristics of the station site as the response characteristics of the instrumentation. If you want to detect very small earthquakes whose dominant frequencies are >10 Hz , you want your sensor to be downhole to escape both surface noise sources and the severe low-pass filtering effects of the near-surface. Sensor location variation can produce an order-of-magnitude in signal/noise ratio, and the differences between professional and amateur equipment will usually not be so great in the frequency band 0.1 - 10.0 Hz. -Edward Walter Williams wrote: > > Hello All, > > Actually the intent of my question was probably not too clear. Since > this event was fairly small, I wondered at what large distance a > small seismic event could be sensed using home-brew instruments in > difference to 'professional' instruments. > Could our friends in Italy sense a 3.0m event in Chatsworth should > they happen to be using home-brew instruments? I infer the premise > of this group is biased along amateur equipment usage. > > Thank you. > > Walt Williams, 97.10.17 > dfheli@.............. > > Woodland Hills, California > USA > > ------- Forwarded Message Follows ------- > Date: Fri, 17 Oct 1997 13:06:52 -0700 > From: Greg Lyzenga > Subject: Re: Chatsworth Quake > To: PSN-L Mailing List > Reply-to: PSN-L Mailing List > > >Hello All, > > > >Yesterday, (Oct. 16, 1997) around 09:00 (AM) PDT in the Chatsworth > >California, USA area (about 25 miles NW of Los Angeles), a 3.0m > >aftershock of the 1994 Northridge event was reported by local area > >news sources. My home is located in a neighbor area of Chatsworth. I > >was surprised when I did not see any posted comments in the PSN-L > >list both yesterday and today regarding this event? I fully expect > >the USGS instruments to sense these small events. But how many of > >the home-brew instruments created and maintained by members of the > >PSN were able to sense this event and how far away? > > > > I picked up the Chatsworth event just fine in Altadena, although it > was not an especially remarkable event, particularly in light of some > of the other bigger local events and teleseisms that have been coming > in over the last few days. > > - Greg > > _____ > Gregory A. Lyzenga, Dept. of Physics, Harvey Mudd College > lyzenga@................. > > _____________________________________________________________________ > > 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 -- 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: Chatsworth Quake Date: Fri, 17 Oct 1997 21:56:11 -0700 Walter, I currently have the gain down on my Lehman in San Jose and 3.5 is too distant to record at 420KM whoever, I had it set at a gain of 2100 following the the Northridge quake and recorded all the 4.2 and larger events. Regards, Steve Hammond PSN San Jose Walter Williams wrote: > > Hello All, > > Actually the intent of my question was probably not too clear. Since > this event was fairly small, I wondered at what large distance a > small seismic event could be sensed using home-brew instruments in > difference to 'professional' instruments. > Could our friends in Italy sense a 3.0m event in Chatsworth should > they happen to be using home-brew instruments? I infer the premise > of this group is biased along amateur equipment usage. > > Thank you. > > Walt Williams, 97.10.17 > dfheli@.............. > > Woodland Hills, California > USA > > ------- Forwarded Message Follows ------- > Date: Fri, 17 Oct 1997 13:06:52 -0700 > From: Greg Lyzenga > Subject: Re: Chatsworth Quake > To: PSN-L Mailing List > Reply-to: PSN-L Mailing List > > >Hello All, > > > >Yesterday, (Oct. 16, 1997) around 09:00 (AM) PDT in the Chatsworth > >California, USA area (about 25 miles NW of Los Angeles), a 3.0m > >aftershock of the 1994 Northridge event was reported by local area > >news sources. My home is located in a neighbor area of Chatsworth. I > >was surprised when I did not see any posted comments in the PSN-L > >list both yesterday and today regarding this event? I fully expect > >the USGS instruments to sense these small events. But how many of > >the home-brew instruments created and maintained by members of the > >PSN were able to sense this event and how far away? > > > > I picked up the Chatsworth event just fine in Altadena, although it > was not an especially remarkable event, particularly in light of some > of the other bigger local events and teleseisms that have been coming > in over the last few days. > > - Greg > > _____ > Gregory A. Lyzenga, Dept. of Physics, Harvey Mudd College > lyzenga@................. > > _____________________________________________________________________ > > 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: Edward Cranswick Subject: Re: Chatsworth Quake Date: Fri, 17 Oct 1997 23:16:54 -0600 Walter- I got carried away with my answer to your first question and forgot the second one (below), but reading Steve Hammond's response jogged my consciousness. Walter Williams wrote: > Could our friends in Italy sense a 3.0m event in Chatsworth should > they happen to be using home-brew instruments? I infer the premise > of this group is biased along amateur equipment usage. At one of the best sites in the world, i.e., with the quietest noise characteristics and best coupled to hardrock basement, the Soviets were able to record a magnitude 3.9 ML nuclear explosion detonated at the US Nevada Test Site (NTS) at their secret seismograph station at Borovoye in Kazakhstan. -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: "David A. Nelson" Subject: Re: Chatsworth Quake Date: Sat, 18 Oct 1997 19:51:19 +1200 Ed, what sort of depth is applicable, 2, 5 , 10 or more metres to see a signigicant improvement. Dave At 08:52 PM 10/17/97 -0600, you wrote: > If you want to detect >very small earthquakes whose dominant frequencies are >10 Hz , you want >your sensor to be downhole to escape both surface noise sources and the >severe low-pass filtering effects of the near-surface. >-Edward 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: GeE777@....... Subject: Re: Chatsworth Quake Date: Sat, 18 Oct 1997 10:29:26 -0400 (EDT) In a message dated 97-10-18 03:54:49 EDT, dann@........ writes: << what sort of depth is applicable, 2, 5 , 10 or more metres to see a signigicant improvement. >> Even though I am new with PSN, I may be able to help you. I have a background wirh seismic exploration Burying our geophones just below the surface should increase the signal to noise ratio by 6db. In normal sedimentary dry soil, the seismic velocity is about 2000 feet per second. When one gets to the water table, the velocity increases to about 6000 f/s. We find to get the geophone in the water table gives us better coupling and reduces the S/N ratio. I want you to know we deal with frequencies that are usually higher than 10 Hz George Erich GeE777@....... Norwalk, California USA _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "David A. Nelson" Subject: Re: Chatsworth Quake Date: Sun, 19 Oct 1997 02:59:00 +1200 Ok George, thanks for the comments, at the moment my three 4.5 Hz geophones are maybe about 12" deep they are encased in a sealed plastic tube so could easily handle going a bit deeper. I have only ~6 - 10" of soil before a thick layer (up to 30 ft) of very hard clay below that are sandstones and limestones. what do you call just.....? when you are refering to phones in the water table you are infering that they are surrounded by wet ground ?? how does that give better coupling ?? from my above comments you could imaging that I would have a hard time finding an accessable watertable depth at my location Now speaking of response My offsider Malcolm, in Christchurch city to the north of me, (which is basically built on a swamp) and I have noticed an interesting response of his 4.5 Hz phone. it is ~6" below surface E/W orient. surrounded by sand and the water table is only a couple of feet further down. We have noticed that his system responds much better to the events ~1000km and greater than the more regional events ( say 100-300km). Which is opposite to the response that I see with the very hard ground that I am on. Interested in your comments TNX Dave > >Even though I am new with PSN, I may be able to help you. I have a background >wirh seismic exploration Burying our geophones just below the surface >should increase the signal to noise ratio by 6db. In normal sedimentary dry >soil, the seismic velocity is about 2000 feet per second. When one gets to >the water table, the velocity increases to about 6000 f/s. We find to get >the geophone in the water table gives us better coupling and reduces the S/N >ratio. I want you to know we deal with frequencies that are usually higher >than 10 Hz > >George Erich >GeE777@....... >Norwalk, California USA > >_____________________________________________________________________ > >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 Hernlund Subject: Re: Chatsworth Quake Date: Sat, 18 Oct 1997 11:29:52 -0700 (MST) On Sun, 19 Oct 1997, David A. Nelson wrote: > thanks for the comments, at the moment my three 4.5 Hz > geophones are maybe about 12" deep they are encased in a sealed plastic > tube so could easily handle going a bit deeper. I have only ~6 - 10" of > soil before a thick layer (up to 30 ft) of very hard clay below that are > sandstones and limestones. Dave, if I were you I would try to unearth a flat portion of that hard rock and cement the tube to it or anchor it somehow. SS and LS rock would probably transmit the waves a whole lot better that anything above it... I wish I had hard rock around here!!! ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: frankcnd@.......... (Frank Condon) Subject: Palmdale Bulge Date: Sat, 18 Oct 1997 14:04:14 -0700 (PDT) Greetings All: Yesterday, there was an earthquake (small one) listed as being on the San Andreas fault near Palmdale, CA . Isn't it unusual to have an earthquake (even small ones) on a section of the fault that is supposedly locked? Check out the item in qustion here! http://quake.wr.usgs.gov/recenteqs/Quakes/sc9026859.html Please let me know what your thoughts are about this one. Thanks, Frank... email to: frankcnd@.......... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "David A. Nelson" Subject: Re: sensor burial Date: Sun, 19 Oct 1997 09:32:24 +1200 John, unfortunately wont find accessable rocks on my property, other than what is in my collection. anyway how's your system going haven't heard from you for a while dave At 11:29 AM 10/18/97 -0700, you wrote: > Dave, if I were you I would try to unearth a flat portion of that hard >rock and cement the tube to it or anchor it somehow. SS and LS rock >would probably transmit the waves a whole lot better that anything above >it... I wish I had hard rock around here!!! > John Hernlund 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: "David A. Nelson" Subject: Re: Palmdale Bulge Date: Sun, 19 Oct 1997 09:43:43 +1200 Frank, You may still get low level activity, that is what is happening on the Apline Fault (the plate boundary) down the spine of the Sth Is. of New Zealand. Technically the fault is locked and it unlocks in a major event every ~250-300 odd yrs. That time is again up in about 20 yrs. But there are still minor, M1-4, events on and around the fault. the section that is "locked" is ~ 300 km long, and there has multiple M7 + events on the sections at either end in the last 100 yrs. Dave At 02:04 PM 10/18/97 -0700, you wrote: >Greetings All: >Yesterday, there was an earthquake (small one) listed as being on the San >Andreas >fault near Palmdale, CA . Isn't it unusual to have an earthquake (even small >ones) on a section of the fault that is supposedly locked? Check out the >item in qustion here! >http://quake.wr.usgs.gov/recenteqs/Quakes/sc9026859.html >Please let me know what your thoughts are about this one. >Thanks, >Frank... 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: frankcnd@.......... (Frank Condon) Subject: Re: Palmdale Bulge Date: Sat, 18 Oct 1997 17:55:19 -0700 (PDT) Hi Dave: Thanks for your explanation about the small tremors along the locked plate boundary. I reasoned this was kind of important because of the significance that is placed on a slightly larger event when it occurs within five miles of the San Andreas fault. They usually will make a statement of a low level watch for the next few days in case of a larger event. I think the cutoff point would be if it was of a magnitude 5.0 or higher and would cause the alert to be active. Best regards, Frank... mail to: frankcnd@.......... >Frank, > You may still get low level activity, that is what is happening on the >Apline Fault (the plate boundary) down the spine of the Sth Is. of New >Zealand. Technically the fault is locked and it unlocks in a major event >every ~250-300 odd yrs. That time is again up in about 20 yrs. But there >are still minor, M1-4, events on and around the fault. > the section that is "locked" is ~ 300 km long, and there has multiple M7 >+ events on the sections at either end in the last 100 yrs. > >Dave > > > >At 02:04 PM 10/18/97 -0700, you wrote: >>Greetings All: >>Yesterday, there was an earthquake (small one) listed as being on the San >>Andreas >>fault near Palmdale, CA . Isn't it unusual to have an earthquake (even small >>ones) on a section of the fault that is supposedly locked? Check out the >>item in qustion here! >>http://quake.wr.usgs.gov/recenteqs/Quakes/sc9026859.html >>Please let me know what your thoughts are about this one. >>Thanks, >>Frank... > >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 > > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Bill Scolnik Subject: Re: Temperature control Date: Sat, 18 Oct 1997 22:14:27 -0400 (EDT) For what it's worth, the Geotech seismometers had a series of resistors in the top of the cover that drew approximately 35 watts which they used as a heater. This was evidently enough to create the necessary temperature gradient inside the enclosure. Bill Scolnik _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: John Hernlund Subject: Re: sensor burial Date: Sat, 18 Oct 1997 20:48:37 -0700 (MST) On Sun, 19 Oct 1997, David A. Nelson wrote: > unfortunately wont find accessable rocks on my property, other > than what is in my collection. > anyway how's your system going haven't heard from you for a while > dave Well, things are going very slowly. I still don't have the benioff in the ground, and the ASU seismometers are almost ready to go if I can ever get the computer people around here to cooperate (computer people are always the hardest to reach and slowest to finish a job on any college campus)! We received Larry's 16-bit card and 3-channel amp, but haven't gotten them going yet. Also, I have been doing some high pressure research in the labs on something called "Impedance Spectroscopy." This is also eating a lot of my time. Some time soon though, I'll send something to the event list that I receive on our seismographs... ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Erich F. Kern" Subject: Thermal Mass/ Low Pass Filter Date: Sun, 19 Oct 1997 12:42:01 -0700 Hi All, We all agree on the importance of thermal insulation to minimize the temperature fluctuations to which seismometers and other instrumentation are subjected. The degree to which the temperature fluctuates within the insulated envelope is also determined by the amount of inert thermal mass. A usefull analogy is a single section R-C low pass filter where the R is the thermal insulation and C is the mass absorbing or dissipating heat. Increase the R or the C and the period gets longer. I am suggesting that the addition of several 1.5 liter bottles of water (secured so they don't tip over onto your seismometer and screw up a nice recording) inside the insulated enclosure will attenuate the amplitude of temperature changes. If there's enough room for a gallon of water in each corner of the enclosure, so much the better. Ideally, this mass should be located at the top of the enclosure to preserve the stratification of air as Karl Cunningham and others pointed out when discussing the placement of resistors to provide heat. This is difficult considering the weight of water, and weight is what thermal storage depends on. I don't know whether bottles of water at the bottom of the enclosure might cause convection currents. They're a diffuse source/sink, not like the point source of a light bulb or resistor, so maybe they wouldn't cause much convection. An insulated enclosure I made for my magnetometers outdoors consists of a plastic 20 gal. trash can with a hole in the bottom just large enough to fit snugly over the mounting pier. The inside is lined with 3" fiberglass R=11 batting and the lid inside surface has a disc of 1.5" styrofoam set in spray-on urethane foam. For thermal mass, I poured in 150 lbs of DRY silica sand. The ~10" dead air space above the sand is occupied with loose fill fiberglass insulation. After a 2 day settling period, a temperature probe buried in the center of the sand showed a 24 hour fluctuation of 7 degrees F. at a time of year when outdoor ambient ranges 50 F. at night to 105 F. at 2 PM. This plastic trash can is dark green and so absorbs and emits heat easily, so I added some aluminized bubble wrap to the outside of the can. Regards, Erich ************************************************************* Please visit our web site at: http://www.dconn.com/FatQuartersSoftware Thank you *************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: GeE777@....... Subject: Re: Thermal Mass/ Low Pass Filter Date: Sun, 19 Oct 1997 17:22:45 -0400 (EDT) In a message dated 97-10-19 15:50:29 EDT, ekern@......... writes: << We all agree on the importance of thermal insulation to minimize the temperature fluctuations to which seismometers and other instrumentation are subjected. >> Why not record the temperature along with your data and subtract from your seismic data any any fluctuations caused by temperature changes? This should reduce the amount of bulky hardware needed. George Erich GeE777@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Walter Williams" Subject: Chatsworth Quake Date: Sun, 19 Oct 1997 19:05:23 +0000 Re; Chatsworth Quake Thanks to All. Walt Williams, 97.10.19 dfheli@.............. Woodland Hills, California, USA _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: Temperature control Date: Sun, 19 Oct 1997 23:26:55 -0700 At 09:59 AM 10/17/97 -0400, Robert Barns wrote: >Hi gang, [snip] > Since a Shackleford-Gunderson operates part of the circuitry at DC, it >might not be as immune to wide temperature swings. Maybe Larry can give us >his thoughts on this. >Bob Barns > Do to its size I think the Lehman would be more sensitive to temperature changes. Living in California reduces the temperature extremes (thank god!) so I can't say for sure how my Lehman and SG sensor would do in temperatures below 0 F or above 100F. I don't think the electronics will be a problem, because I use high quality op-amps etc. The SG sensor is extremely sensitive to air currents inside the box that covers the senor. This can be fix by filling the inside of the box with foam rubber so that it occupies as much of the free space as possible without touching the sensor itself. -Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: prewar Subject: Re: Thermal Mass/ Low Pass Filter Date: Mon, 20 Oct 1997 14:02:42 +0100 Erich F. Kern wrote: > Hi All, > We all agree on the importance of thermal insulation to minimize the > temperature fluctuations to which seismometers and other instrumentation > are subjected. The degree to which the temperature fluctuates within the > insulated envelope is also determined by the amount of inert thermal mass. > .......... I am suggesting that > the addition of several 1.5 liter bottles of water (secured so they don't > tip over onto your seismometer and screw up a nice recording) inside the > insulated enclosure will attenuate the amplitude of temperature changes. If > there's enough room for a gallon of water in each corner of the enclosure, > so much the better. Ideally, this mass should be located at the top of the > enclosure to preserve the stratification of air as Karl Cunningham and > others pointed out when discussing the placement of resistors to provide > heat. This is difficult considering the weight of water, and weight is what > thermal storage depends on................................ > > An insulated enclosure I made for my magnetometers outdoors consists of a > plastic 20 gal. trash can with a hole in the bottom just large enough to > fit snugly over the mounting pier. The inside is lined with 3" fiberglass > R=11 batting and the lid inside surface has a disc of 1.5" styrofoam set in > spray-on urethane foam. For thermal mass, I poured in 150 lbs of DRY silica > sand. The ~10" dead air space above the sand is occupied with loose fill > fiberglass insulation. After a 2 day settling period, a temperature probe > buried in the center of the sand showed a 24 hour fluctuation of 7 degrees > F. at a time of year when outdoor ambient ranges 50 F. at night to 105 F. > at 2 PM....................... > Regards, > Erich Hi Erich, I like the water idea. I wonder if thermal blocks, of the type used in electric night storage heaters would have greater thermal inertia? I shall be piling up the bricks, and collecting water bottles soon!! Perhaps carefully placed BAFFLES may assist in preventing air currents just where they are least wanted. Your 7deg F temp variation is very impressive when compared with your 55 deg. ambient temp. variation. Regards, Albert Noble (England). _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Charles R. Patton" Subject: Re: Thermal Mass/ Low Pass Filter Date: Mon, 20 Oct 1997 09:31:34 -0700 prewar wrote: >... I like the water idea. I wonder if thermal blocks, of the type used > in electric night storage heaters would have greater thermal inertia? > ... Albert Noble (England). I would wonder if thermal blocks incorporate phase-change materials. If so, then they are probably higher temperature melting point salts and would have an interesting hysteresis effect on the process when (if) you take them through the phase-change temperature. If you don't take them through the phase-change, then my guess is that you would be paying excessive dollars (pounds!) for the thermal inertial. Water would be just as effective and much cheaper. Also with winter coming on (at least in the Nothern hemisphere), don't forget the antifreeze (unless you're prepared to use thermal storage blocks with a phase-change temperature of 0 degrees C and the nasty side effect of a strong temperature coefficent of expansion around the phase change!) Charles R. Patton patton@......... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: GeE777@....... Subject: Re: Palmdale Bulge Date: Mon, 20 Oct 1997 14:09:22 -0400 (EDT) In a message dated 97-10-18 17:08:58 EDT, frankcnd@.......... writes: << Yesterday, there was an earthquake (small one) listed as being on the = San=20 Andreas fault near Palmdale, CA >> Hello All Please refer to the map in--- http://quake.wr.usgs.gov/recenteqs/ It appears there is more than the average number of small quakes in South= ern California during the last week. Much of these small quakes are near the area of the =91=92locked zone=92 on the San Andreas Fault. Ridgecrest, = at the south end of the Sierra Nevada Fault Zone has been active with small quak= es for quite some time. Note that now these quakes extend up north along th= e Sierra Nevada Fault Zone and south crossing the Garlock fault. I underst= and the Garlock Fault is a strike slip fault with the south side being east i= n respect to the north side. Yet this line of small quakes seems to be a n= ew extension of the Sierra Nevada Fault Zone as it is not offset by the Garl= ock Fault. Note a number of small quakes near the =91=92bend in the San Andr= eas Fault=92=92 , which is also in the =91=92locked=92=92 area. I don=92t want to =91=92cry wolf=92=92 unnecessarily, however should thes= e small quake patterns be ignored? Are these indications of the =91=92Big One=92=92? = Should there be more than just a low level alert for Southern California at this time?= I would advise all in Southern California to prepare for an emergency situation. Keep vehicle fuel tanks more than half full at all times and = be ready to shut off gas, electricity and water in homes and businesses in a hurry. George Erich GeE777@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Karl Cunningham Subject: Re: Thermal Mass/ Low Pass Filter Date: Mon, 20 Oct 1997 11:16:42 -0700 With the talk of thermal mass inside the enclosure, something comes to mind... I think there is a potential problem if the thermal mass is too large. When the outside air temperature is rising, a situation could exist where the air below the thermal mass is warming faster than the thermal mass itself. If the air below it ever got to a higher temperature than the thermal mass, there would be convection currents -- cooler air falling from the thermal mass. If the heater is mounted such that it heats the thermal mass, I think this might help since in a constant-temperature environment the thermal mass will always be warmer than any air in the enclosure. Under warming conditions though, the air in the enclosure will be warming, and so will the thermal mass -- but at a slower rate. What's important is to make sure the temperature of the air doesn't overtake the temperature of the thermal mass. I don't have a very good feel for this but, as someone suggested, measurements of the thermal time constants would be a good start. Karl Cunningham La Mesa, CA. PSN station #40 karlc@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: GeoMonitr@....... Subject: Re: HAM interested in earthquake prediction Date: Mon, 20 Oct 1997 14:20:52 -0400 (EDT) I DID check out the number of lost dogs and cats from the Humane Society in Santa Clara, Calif. around the time of the Loma Prieta quake, and there was a slight increase prior to the event, but not statistically significant. I did the same thing with the lost cat and dog count from the San Jose Mercury News, and there was a LARGE increase, but again, not statistically significant. Someone from the USGS suggested using the egg and milk counts from factory farms. These folks keep detailed records of grain consumed, output, weight fluctuations, etc. ANY event that affects their level of contentment (read here quake precursors) should be reflected in the production of eggs, milk, etc. Again, a simple phone call, but who's going to do it? Vince _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: GeoMonitr@....... Subject: Re: HAM interested in earthquake prediction Date: Mon, 20 Oct 1997 14:28:36 -0400 (EDT) The Haichang (sp?) quake was the only real success the Chinese had with quake prediction. About a year after that successful warning (thousands of lives saved by evacuation) there was another deadly quake that was NOT predicted, and I think they lost 100,000 people. The Haichang quake had many foreshocks, and the peasant population was trained in observing and reporting anomalous behavior in their livestock - - remember these are people close to the earth and their animals. All this is well documented in Tributsch's "When the Snakes Awake." The fellow in LA is Jim Berkland, and he was in the San Jose area (Never to be confused with LA) but has now retired and moved to Valley of the Moon, up in the wine country north of San Francisco. His method relied on window of hyperactivity caused by the moons' tidal forces, combined with the lost pet count. He's had some success, but was resoundingly ignored by the scientific community. My personal belief is that humans and animals may be able to detect electromagnetic signals from quake precursors, but only a fraction of quake exhibit such precursors. Vince _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "David A. Nelson" Subject: That mob microsoft Date: Tue, 21 Oct 1997 17:25:56 +1200 hi all, a little more humor to help the week go by, BTW its great to see the US courts standing up to Microsoft, $1.5 million a day fine ouch.... There was a pilot flying a small single engine charter plane, with a couple of very important executives on board. He was coming into the Seattle airport through thick fog with less than 10 miles visibility when his instruments went out. So, he began circling around looking for a landmark. After an hour or so, he starts running pretty low on fuel and the passengers are getting very nervous. Finally, a small opening in the fog appears and he sees a tall building with one guy working alone on the fifth floor. The pilot banks the plane around, rolls down the window and shouts to the guy, "Hey, where am I?" To this, the solitary office worker replies, "You're in a plane." The pilot rolls up the window, executes a 275 degree turn and proceeds to execute a perfect blind landing on the runway of the airport 5 miles away. Just as the plane stops, so does the engine as the fuel has run out. The passengers are amazed and one asks how he did it. "Simple," replies the pilot, "I asked the guy in that building a simple question. The answer he gave was 100 percent correct but absolutely useless, therefore, that must be Microsoft's support office and from there the airport is just five miles due East." Chow 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: "Erich F. Kern" Subject: Re: That mob microsoft Date: Mon, 20 Oct 1997 23:18:53 -0700 Dave, It's a mystery to me why anyone would express such obvious glee due to a large fine being levied against Microsoft. Where do you think that money is coming from? Or didn't you think that one through? Erich Kern ---------- > From: David A. Nelson > To: psn-l@............. > Subject: That mob microsoft > Date: Monday, October 20, 1997 22:25 > > hi all, > a little more humor to help the week go by, > > BTW its great to see the US courts standing up to Microsoft, $1.5 > million a day fine ouch.... > > > > > > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Michael Chang Subject: Re: That mob microsoft Date: Tue, 21 Oct 1997 02:45:03 -0700 The fact that we'll ultimately share the cost of such fines, doesn't lessen the necessity of sending Microsoft the message of what it means to be a responsible corporate citizen, and that they are part of the community.. and don't own it. At 11:18 PM 10/20/97 -0700, you wrote: >Dave, >It's a mystery to me why anyone would express such obvious glee due to a >large fine being levied against Microsoft. Where do you think that money is >coming from? Or didn't you think that one through? >Erich Kern > > > >---------- >> From: David A. Nelson < >> To: psn-l@............. >> Subject: That mob microsoft >> Date: Monday, October 20, 1997 22:25 >> >> hi all, >> a little more humor to help the week go by, >> >> BTW its great to see the US courts standing up to Microsoft, $1.5 >> million a day fine ouch.... >> >> >> >> >> >> > >_____________________________________________________________________ > >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: prewar Subject: Re: HAM interested in earthquake prediction Date: Tue, 21 Oct 1997 11:10:01 +0100 GeoMonitr@....... wrote: > > ....................................... > My personal belief is that humans and animals may be able to > detect electromagnetic signals from quake precursors, but > only a fraction of quake exhibit such precursors. > > Vince > > _Hi Vince, There now appears to be much evidence that UFO sightings can mostly be explaned in terms of light caused by electomagnetic effects in highly stressed rocks. Tests done in labs. crushing rock, shows that they can emit in the visible spectrum. A very good book on this subject for all interested in earthquake precursors is..... ....EARTH LIGHT REVELATION by Paul Devereux. It sounds cranky, but it is not. It puts to rest all the UFO mumbo jumbo, and is very interesting re earthquakes. Published in England, BUT distributed in USA by.... ....Sterling Publishing, 387 Park Ave. South, NY. In MARFA, Texas, the (UFO?) lights are FREQUENT, but it is also near to earthquake areas. A map of your country showing earthquake centres and areas where moving lights have been seen, appears to indicate that more UFO's have been sighted near the maximum earthquake activity zones..... ......I wonder why?...! ( The UFO enthusiast will no doubt explain, that this is because the aliens wish to study our 'Quakes!!! Well, why not? ). Regards, Albert Noble (England) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: GeE777@....... Subject: NOTICE Date: Tue, 21 Oct 1997 16:07:40 -0400 (EDT) Printed in the Los Angeles Times, October 21, 1997 CALIFORNIA EARTHQUAKE AUTHORITY P. O. BOX 2082 KEENE, NEW HAMPSHIRE 03431 George Erich GeE777@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Stephen Caruso Subject: Re: HAM interested in earthquake prediction Date: Tue, 21 Oct 1997 22:08:37 -0400 (EDT) Perhaps one should think why these animals are sensitive. They are smaller, and more likely to be sensitive to their environment, their everysense is tuned to survival! STEPHEN CARUSO CET KB8UGH "Coincidence is a shortsighted mental delusion" _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Bob Fryer Subject: Re: HAM interested in earthquake prediction Date: Tue, 21 Oct 1997 19:38:47 -0700 (PDT) Hello, On Tue, 21 Oct 1997 11:10, prewar < wrote: >GeoMonitr@....... wrote: >> ....................................... >> My personal belief is that humans and animals may be able to >> detect electromagnetic signals from quake precursors, but >> only a fraction of quake exhibit such precursors. >> >> Vince > _Hi Vince, > There now appears to be much evidence that UFO >sightings can mostly be explaned in terms of light caused >by electomagnetic effects in highly stressed rocks. > >Tests done in labs. crushing rock, shows that they can >emit in the visible spectrum. A very good book on this >subject for all interested in earthquake precursors is..... >...EARTH LIGHT REVELATION by Paul Devereux. >It sounds cranky, but it is not. It puts to rest all the >UFO mumbo jumbo, and is very interesting re earthquakes. >Published in England, BUT distributed in USA by.... >...Sterling Publishing, 387 Park Ave. South, NY. > >In MARFA, Texas, the (UFO?) lights are FREQUENT, >but it is also near to earthquake areas. > A map of your country showing earthquake centres >and areas where moving lights have been seen, >appears to indicate that more UFO's have been sighted >near the maximum earthquake activity zones..... >..... < > Regards, > Albert Noble (England) =46irst, my experience suggests that Albert's confidence in the works of Paul Devereux is justified. And I agree that a significant number of UFO reports are due to stressed rocks, but I think that 'mostly' is a bit of a stretch. There are many other factors. On Vince's comments, I go much farther: Yes, humans and animals ARE able to detect electromagnetic signals from quake precursors; but, _no_ to "only a fraction of quakes exhibit such precursors." I now think that it is safe to say that all earthquakes exhibit electromagnetic precursors, albeit there can be very wide variations in the signal characteristics. Instrumentation and recording capabilities available to the general public are simply not adequate for the needs. (And estimates of the death toll for the 1976 Tangshan quake go as high as 750,000. The Chinese admitted to 240,000, I believe.) My opinions are based on information that is not easily available to, or perhaps not understood by, the casual investigator: HelveticaHazenHelvetica, Robert M., "Perovskites," Scientific American, v258, 6, June 1988, pp74-81. "...natural superconducting ceramic minerals.... common in the earth.... exhibit a wide range of electrical properties...." See p76, columns 2 & 3. When you understand that some perovskites change shape, thus generating mechanical (acoustic) energy, and you study the Helmholtz resonator, you can then appreciate harmonic effects that drive animals from enclosed structures including burrows. Back to EM energy, ELF/brainwave frequencies have surprising characteristics: they penetrate nearly everything, and do not obey the 'inverse square' law. They travel great distances with little attenuation. Given this, with the many faults around the earth, it is a blessing that we don't 'hear' all the noise. Kirschvink demonstrated that magnetite in the brain offers a mechanism for reception of signals. Growing evidence strongly suggests that sensitivity involves both psychological and immunological aspects. ------------------ Last week, an investigator whom I had not heard of, stated that his equipment has allowed him to make VERY accurate predictions for several years. He gave a very promising reply to this query: We, including the earth sensitive people, are very interested to hear what you have been doing. Having focused on this area since 1982, I am well aware that the technical capability exists to measure the precursory phenomena to which the sensitives react. Have you seen the article which I posted in the CompuServe Earth Forum library several years ago, regarding the U.S. Navy? Have you run into any trouble with the military during the development of your equipment? Is this equipment/method[s] similar to that of David Farnsworth and Adam Trombly? Elizabeth Rauscher and William Van Bise? The VAN group? Are you willing to share some descriptions of your work? I realize that there may be some proprietary concerns. Where might I find the published references to your work? My own efforts over the past 18 months have been heavily weighted towards gathering the experiential material, from the sensitive people, which I have followed towards its psychological and physiological underpinnings. Note that my interests in perception predate Charlotte King's experience with Mount Saint Helens. ------------------------ Towards the true sensory capability of humans, I offer this recent post of information from an eminent researcher, to the "sensitive" people: Hi (Sensitives), The purpose of sending this item is to emphasize that the nature of our sensitivity to Electromagnetic energy *also* includes the cellular level. Of particular interest is the comment, **In other words, a threshold might not exist in such a system.** This is found at the end of a paragraph about 2/3 through the article. Translated: We _may_ react, in some fashion, to ANY alterations of EM fields, including stressed faults and brain waves. Take care, Bob http://www.mk.net/~mcf/mind_net/mnindex.htm =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D MindNet Journal - Vol. 1, No. 50 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D V E R I C O M M / MindNet "Quid veritas est?" =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D The views and opinions expressed below are not necessarily the views and opinions of VERICOMM, MindNet, or the editors unless otherwise noted. The following is reproduced here with the express permission ofthe publisher, Frontier Sciences, Temple University. Permission is given to reproduce and redistribute, for non-commercial purposes only, provided this information and the copy remain intact and unedited. Editor: Mike Coyle < Contributing Editors: Walter Bowart Alex Constantine Martin Cannon Assistant Editor: Rick Lawler Research: Darrell Bross =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D WHISPERING BETWEEN CELLS: ELECTROMAGNETIC FIELDS AND REGULATORY MECHANISMS IN TISSUE By W. Ross Adey [MD] VA Medical Center & University School of Medicine, Loma Linda, California ---------------------------------------------------------------- Over the past 20 years, a series of observations has pointed with increasing certainty to an essential organization in living matter, physical in nature at a far finer level than the structural and functional image defined in the chemistry of molecules. This is indeed a new frontier. It neither ignores nor neglects the great accomplishments across centuries of biological research, studies that have led to our present knowledge of the exquisite fabric of living tissues, focused on the chemistry and molecular biology of cell ultrastructure. Rather, this new knowledge appears to build logically and sequentially from all that has gone before. Yet in many respects, it has been an uncharted ocean in both biological and physical sciences. Research with millimeter waves also supports concepts of free radical interactions in biological systems. At frequencies in the range 10 to 1000 GHz, resonant vibrational or rotational interactions, not seen at lower frequencies, may occur with molecules or portions of molecules. Studies in yeast cells over the past 15 years in athermal millimeter wave fields by Grundler and Kaiser(10) have shown that growth appears finely "tuned" to applied field frequencies around 42 GHz, with successive peaks and troughs at intervals of about 10 MHz. -- Huge SNIP -- In recent studies, they noted that the sharpness of the tuning increases as the intensity of the imposed field decreases; but the tuning peak occurs at the same frequency when the field intensity is progressively reduced. Moreover, clear responses occur with incident fields as weak as 5 picowatts/cm2. In a recent synthesis emphasizing nonthermal interactions of EM fields with cellular systems, Grundler et al.,(3) present models of the transductive sequence of EM field transductive coupling, based on magnetic field-dependent chemical reactions, including cytochrome-catalyzed reactions that involve transient radical pairs, and production of free radicals, such as reactive oxygen and nitric oxide, leading to a further highly cooperative amplification step.=20 Based on Frohlich's(11) model of interactions between an imposed field and high frequency (1012 Hz) intracellular van der Pol oscillators, they conclude that "imposed fields can be active even at intensities near zero." **In other words, a threshold might not exist in such a system.** Beyond the low energies of EM fields in the first transductive step, amplification of low-frequency signals at cell membranes relates to selective responses seen as windowed phenomena in both frequency and amplitude domains. Contending models have considered cyclotron resonance and calcium coordination compound interactions. -- Large SNIP -- Future research on submolecular transductive coupling will be diversified and increasingly dependent on new technologies, such as high resolution magnetic resonance spectroscopy and electro-optical techniques. These approaches may answer such challenging problems as structural modifications during receptor-ligand binding, vibration modes in cell membrane lipoprotein domains during excitation(14) and possible coherent millimeter wave emissions accompanying enzyme action. There is a reasonable prospect that bioelectromagnetics may emerge as a separate biological discipline, offering a unique vehicle in the development of a physical, as distinct from a chemical, biology. In little more than a century, our biological vista has moved from organs to tissues, to cells, and most recently to the molecules that are the exquisite fabric of living systems. There is now a new frontier, more difficult to understand, but of vastly greater significance. It is at the atomic level that physical processes, rather than chemical reactions in the fabric of molecules, appear to shape the transfer of energy and the flow of signals in living systems(15). References 1. Adey, W. R., 1988. Physiological signalling across cell membranes and cooperative influences of extremely low frequency electromagnetic fields. In: Biological Coherence and Response to External Stimuli, H. =46rohlich, ed., Heidelberg, Springer-Verlag. pp. 148-170. 2. McLauchlan, K., 1992. Are environmental magnetic fields dangerous? Physics World, January, 1992, 41-45. 3. Grundler, W., Kaiser, F., et al., 1992. Mechanics of electromagnetic interaction with cellular systems. Naturwissenschaften 79, 551-559. 4. Adair, R. K., 1991. Constraints on biological effects of extremely-low-frequency electromagnetic fields. Phys. Rev. A. 43(2), 1039-1048. 5. Bialek, W., 1983. Macroscopic quantum effects in biology. Ph.D. Thesis, Department of Chemistry, University of California, Berkeley.=20 250 pp. 6. Adey, W. R., 1992a. Collective properties of cell membranes. In: Interaction Mechanisms of Low-Level Electromagnetic Fields in Living Systems, B. Norden, C. Ramel, eds. Royal Swedish Academy of Sciences, 1989. Oxford University Press. pp. 47-77. 7. Adey, W. R., 1992b. ELF magnetic fields and promotion of cancer: experimental studies. In Interaction Mechanisms of Low-Level Electromagnetic Fields in Living Systems, B. Norden, C. Ramel, eds. Royal Swedish Academy of Sciences, 1989. Oxford University Press. pp. 23-46. 8. Frohlich, H., 1986. Coherent excitation in active biological systems. In: Modern Bioelectrochemistry, F. Gutmann, H. Keyzer, eds. New York: Plenum. pp. 241-261. 9. Adey, W. R., 1981. Tissue interactions with nonionizing electromagnetic fields. Physiol. Rev. 61, 435-514. 10. Grundler, W., Kaiser, F., 1992. Experimental evidence for coherent excitations correlated with cell growth. Nanobiology 1, 163-176. 11. Frohlich, H., 1986. Coherence and the action of enzymes. In: The =46luctuating Enzyme, G. R. Welch, ed. New York: Wiley. pp. 421-449. 12. Liboff, A. R., 1985. Cyclotron resonance in membrane transport.=20 In: Interactions Between Electromagnetic Fields and Cells. New York: Plenum Press. pp. 281-296. 13. Lednev, V. V., 1991. Possible mechanisms for the influence of weak magnetic fields on biological systems. Bioelectromagnetics 12, 71-76. 14. Christiansen, P. L., Eilbeck, J. C., et al., 1992. On ultrasonic Davydov solitons and the Henon-Heiles system. Phys. Lett. A 166, 129-134. 15. Trullinger, S. E., 1978. Where do we go from here? In: Solitons and Condensed Matter Physics, A. R. Bishop, T. Schneider, eds. Berlin, Springer-Verlag. pp. 338-340. If you wish to receive a copy of the Vol.3, No.2 issue of our journal, please e-mail me your street address and I will forward you a copy. I trust that you will find the above paper interesting and I look forward to any comments. Dr. Adey is to be commended for the fine work that he has done in this field. My best wishes to all, Nancy Kolenda, Coordinator Center for Frontier Sciences, Temple University, < ---------------------------------------------------------------- MindNet Journal Archive Filename: [mn150.txt] =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D End matter snipped. ----- earthquake WARNING research ----- --- animals, people, scientific evidence --- --- http://www.teleport.com/~bfryer --- _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: Re: Thermal Mass/ Low Pass Filter Date: Wed, 22 Oct 1997 09:12:38 -0400 Albert, = Please note that the temperature stabilization effort of Eric Kern was applied to a housing for , not seismometers. These two types of sensors have very different responses to temperature and temperature changes. I have done some work with the magentometer Eric is talking about. Its= output frequency is proportional to the magnetic field. The output freq.= at constant field also changes with temperature, i.e, it has a considerab= le temperature coefficient. When trying to see the smallest changes in fiel= d (magnetic storms, etc.), temperature changes confuse the interpretation = so that reducing the rate of change of temperature and the total temperature= swing helps. Thermostatting the sensor would be a greater help. The scheme I have tried is to strap a thermistor to the magnetometer and use = a reasonable amount of insulation. The temperature coefficient of the magnetometer was measured (crudely) and a computer records the frequency and the thermistor resistance. The program then calculates the freq. correction for the temperature indicate= d by the thermistor (as was suggested by George Eric). This improved the data quite a bit without the complication of thermostatting but thermostatting would be better if done carefully. Seismometers are only slightly (if at all) sensitive to temperature changes per se. As far as I'm aware, no professional seismometers are thermostatted (although my knowledge of these things is very limited). Th= ey are exquisitely sensitive to air currents, e.g., those due to temperature= gradients in their surroundings. Thus, it is far more important to minimize air currents than to reduce temperaure changes or the rate of temperature change. This is what Larry does by stuffing the space around= his S-G's. Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: TMichel917@....... Subject: Address GEOSense Date: Wed, 22 Oct 1997 13:23:46 -0400 (EDT) Hi all, I'm looking for information about the GEOSense seismographs. Is somebody there who can send me the new GEOSense faxnumber? Thanks! Torsten _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: prewar Subject: magnetometers/seismometers & 'tilting' at the moon. Date: Wed, 22 Oct 1997 20:02:34 +0100 Robert L Barns wrote: > Albert, > Please note that the temperature stabilization effort of Eric Kern was > applied to a housing for , not seismometers. These two > types of sensors have very different responses to temperature and > temperature changes. > I have done some work with the magentometer Eric is talking about. Its > output frequency is proportional to the magnetic field. The output freq. > at constant field also changes with temperature, i.e, it has a considerable > temperature coefficient. When trying to see the smallest changes in field > (magnetic storms, etc.), temperature changes confuse the interpretation so > that reducing the rate of change of temperature and the total temperature > ........................snip > Seismometers are only slightly (if at all) sensitive to temperature > changes per se. As far as I'm aware, no professional seismometers are > thermostatted (although my knowledge of these things is very limited). They > are exquisitely sensitive to air currents, e.g., those due to temperature > gradients in their surroundings. Thus, it is far more important to > minimize air currents than to reduce temperaure changes or the rate of > temperature change. This is what Larry does by stuffing the space around > his S-G's. > Bob Barns Hi Bob, Thanks for above advice. Reducing air currents is now my priority. My Hall-Effect sensors are the most temp. stable devices which I could obtain from electronic suppliers, here in England. Also intend to keep enclosure near temp.stable in winter/summer. The reason for Hall-Effect is an interest in measuring earth TILT as well as 'quakes. (I can imagine the frowns on many brows now. ) I'm probably over ambitious in this, but as a green beginner my enthusiasm shows no bounds. ( Yet !! ) My 1898 (!) book on seismology talks of earth tilt caused by the passage of the moon, so I wish to investigate. (by 'averaging' data every hour to look for non drift, non weather influences.). Regards, Albert Noble (England) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: peaches@............ (Donna Whitaker) Subject: Re: Address GEOSense Date: Wed, 22 Oct 1997 09:17:14 -1000 (HST) Torsten, Geosense 115 W. California Blvd. #304 Pasadena, CA. 91105 Ph. (818) 388-2826 No FAX listed. Models: PS-2-V Vertical Single Axis $495.00 PS-2-H Horz. Single Axis $545.00 PS-2-2A Two Axis (H-H or V-H) $795.00 PS-2-T Triaxial (H-H-V) $1,125.00 Extended low frequency response options. Hope this helps. Tony >Hi all, > >I'm looking for information about the GEOSense seismographs. Is somebody >there who can send me the new GEOSense faxnumber? > >Thanks! > >Torsten > >_____________________________________________________________________ > >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: GeE777@....... Subject: Re: magnetometers/seismometers & 'tilting' at the moon. Date: Wed, 22 Oct 1997 17:40:17 -0400 (EDT) Hello, Before I retired from exploration geophysics, I could give a technician lat and long, time and date and he would be able to tell me what affect the ''earth tide'' (not sea tide) would have on my gravity data at that point and time on the earth. It was calculated in a program in our mainframe computer. I'm sure thase programs must still exist and must be improved. Can anyone help? George Erich GeE777@....... In a message dated 97-10-22 15:09:20 EDT, prewar@.............. writes: << The reason for Hall-Effect is an interest in measuring earth TILT as well as 'quakes. (I can imagine the frowns on many brows now. ) I'm probably over ambitious in this, but as a green beginner my enthusiasm shows no bounds. ( Yet !! ) My 1898 (!) book on seismology talks of earth tilt caused by the passage of the moon, so I wish to investigate. (by 'averaging' data every hour to look for non drift, non weather influences.). >> _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Erich F. Kern" Subject: Thermal Mass Date: Wed, 22 Oct 1997 14:57:20 -0700 Bob Barns et al, Bob, you've pointed out something I haden't thought of which is one of the benefits of this forum. The bottom line of the point you made is that minimizing temp gradients and the convection currents which are driven by gradients are far more important than temp stability per se. Actually, the addition of thermal mass at the bottom of the enclosure could create convection currents as the outer walls of the box cool down at night. Karl Cunningham mentioned this effect too. OK, OK I take it back about adding thermal mass. As for magnetometers, a 7 degree / 24 hour temp range is something I can live with. I sited mine outdoors 80 feet from the nearest building to avoid power line transients, etc, and had thought about a thermostatically controlled heater but abandoned the idea in favor of insulation and thermal mass which has worked very well. I can see now that it might make things worse in a seismo enclosure. Regards, Erich Kern *************************************************************** Please visit our web site at: http://www.dconn.com/FatQuartersSoftware Thank you *************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Roger Griggs Subject: Re: New beta release of WinQuake and SDR. Date: Wed, 22 Oct 1997 18:52:09 -0700 Larry, I have loaded your new versions of sdr and winqk32 and if you have not already found out from someone else there are some bugs in the winqk32. 1. There is no EXIT on the file menu drop down. 2. In the file menu, below "Print Margins" it seems to automatically add a list of files and directories (about 9 on mine). As you run the cursor down the list it automatically loads the contents of the first dir on the list into the OPEN FILE dialog box in the main window instead of letting you click on the one you want. 3. I get a timeout error when trying to retreave a replay from winquake. I will recheck your instructions again to make sure I have not missed something. I have added the two channel info into the setup and the replay button is active. Roger At 10:04 PM 10/14/97 -0700, you wrote: >Greetings, > >I just got finished with the next release of WinQuake, version 2.5, and >would like some beta testers to try it out. I also have a new beta release >of SDR, version 2.4, that goes along with the WQ release. > >The WinQuake release has two new features and some bug fixes. The two bug >fixes are: > >The Great Circle Distance Calculate dialog box was displaying bogus numbers >for the azimuth calculation. Thanks to Robert Barns for reporting this bug. > >The second bug was around the Data Integration feature. On 16 bit versions >it would crash on some event files. Thanks to Bob Lewis for reporting this >one. > >The two new features are both network related. If you are going to try this >release please save this email message. Its the only documentation I have >for the new features. > >The first feature allows the user to directly access report information >over the Internet. It uses the UNIX finger service (TCP/IP port 79) to get >report information directly from the source. This report information has >event information (location, time of origin etc) that can be used to update >event files. Before you had to use some other method to get the report into >a file local to the system and then have WinQuake read it in. With this new >feature all you have to do is select the finger server/host in a dialog box >and WinQuake will retrieve the information directly over the Internet. It >save the report/finger information in a file and then parse out the event >information and displays it in a list box. The report information can then >be used to fill in the header information of an event file or used in the >second new feature below. > >There's one big problem... This feature is only supported in the 32 bit >version. For WinQuake to access information over the Net it needs to have >access to sockets. The sockets under Win95 and NT are easier to deal with. >Since the 16 bit version of Windows is now obsolete I'm not going to spend >anytime supporting it. Sorry... > >To use this feature all you need to do is go to the Report dialog box. You >can use the Report tool bar icon or the File / Report menu item to open >this dialog box. There you will see a new button called "Load Network >Report". This button is grayed-out in the 16 bit version. After selecting >this button you will see a new dialog box. If you have the NETWORK.DAT file >in the same directory as WQ you should a list of finger commands/host names >in the list box. If you double click (or use the "Connect" button) on one, >WQ should attempt to connect to the finger server and download the file. >Obviously you will need to be logged onto the net to get any data back. If >everything works as planed the dialog box will close up when it finishes >collecting the data. > >The Report dialog report list should now have the new event information in >it. If there are any errors, the Network dialog box will stay open and an >error message should show up in the Status line. The "Directory" button >sets the default location for the report files that are created using this >feature. The actual name of the report file is based on the host name. I >replace all of the "." in the host name with a "_" and then tag on the end >".rpt". This file is then saved using the directory specified by this button. > >The Add, Del and Save buttons are used to manage the NETWORK.DAT file. This >file holds the information needed for the feature to work. This file must >be located in the same directory as the WQ exe file. You also need the >REPORT.DAT file. This file has the parsing information use to extract the >event information. It also needs to be in the same dir. as the WQ exe file. >Both DAT files are in the beta zip file. > >In the future WinQuake will be able to get other information using direct >connection to the Internet. This could be event files or other report >information that is not available as a finger service. I would like to get >the norcal.list file directly using http. This file has all of the local >events, even the ones smaller then the 2.0 cutoff of the >quake@.............. list. This list is available using http and maybe ftp. >What I need to do is figure out the protocol of both so I can have WQ use >these protocols to download data/files. > >The second new feature is only for SDR users. It is supported in both the >16 and 32 bit versions. This feature allows the user to request/replay an >event file using WinQuake. To use this feature you must have your SDR and >main Windows system (Win3.1, Win95 or NT) networked together using two NIC >cards. Many of the sdr users have there systems networked so I thought I >would add this feature. It uses the same SDR feature used to implement the >request data form at http://psn.quake.net/request.html. This form allows >the user to extract a PSN formatted event file from my SDR systems based on >a start time, number of minutes to save, channel etc. SDR then uses this >info and creates an event file. Its similar to doing a replay, but remotely. > >Setting things up to get this feature working is a little complicated so >here it goes... > >First you need to get the two systems networked together. I would suggest >loading Win95 on both systems if you are going to try doing this. In the >beta release of SDR there is a netwin95.txt file that explains how to do >this. Another file you need too read is sdrwin95.txt. This file explains >how to run SDR in the DOS only mode of Win95. If you get the network stuff >working you should be able to map a drive letter, say "D:" on your SDR >system so that it is the same drive as the "C:" (or other local disk) drive >on your Windows system. Another words, if you have a dir/path called >c:\sdr\event\ on your Windows system, and, if you have your sdr system >maps the D: drive to be the same as the C: drive on the other system, then, >d:\sdr\event\ will be the same directory, and, files can be shared between >the two systems. > >For this feature to work you will need two directories. One will hold the >temporary request information file that SDR reads for the replay >information, and the other will hold the returned event file. Create two >directories like c:\sdr\event and c:\sdr\request on your Windows system. >Now enter the shared drive and path information in the field "Request >Control File Path" under the F5 settings in SDR. If the SDR D: drive = the >C: drive on the Windows system then enter "d:\sdr\request\" for that menu >item. That's all you need to do the SDR side of things. SDR will look for a >request file in that dir. every 10 seconds. If it finds one, it tries to do >the replay and create the event file. > >For more information on how the request process works in SDR, please read >the request.txt file that comes with the beta release of SDR. > >Now for WinQuake. When WQ firsts starts up it looks for a file called >REPLAY.DAT in the same dir. as WQ runs out of. If it finds it, then the new >"Replay" button in the File Open dialog box will be enabled. If the file is >not there this button will be disabled. Since this button will be disabled >when you run the new WQ for the same time you will have to use the menu >item called "Replay Setup" under the File menu items. > >This dialog box is used to create and manage the REPLAY.DAT file. The first >item in this dialog box is the returned event file path that SDR will use >to place files in. Use the "Change" button to select the directory that you >will be using, like c:\src\event, to hold the returned event files in. Next >you need to add the channel information for each of your sensors you are >running. For each channel select the "Add" button. In the Add Replay info >dialog box add the File extension for that channel, like LC1. If you only >have one sdr system keep the SDR system number at 1. For the Control File >directory use the "Change" button and select the dir. you will be using for >the request control file, like c:\sdr\request. > >After entering the replay info you should be able to do a replay. The >Replay button should now be enabled in the File Open dialog box. In the >Replay dialog box you will see a series of edit boxes for the start time, >save length, channel etc. After filling in the start time and channel press >the "Replay" button. WQ will create a request file for SDR to read and then >waits for the event file to be created by SDR. If after ~40 seconds there >is no event file found, WQ will time out. If it does find the event file it >will close out the Replay dialog box and open the event file. The "Report" >and "Report Time" can be used to set the starting time based on the >currently selected report time. The Save Default check box is used to save >selected fields, marked with a * in the group box name, as default settings >for the next time you run WQ. > >The SDR beta release as only minor changes in it. While you do not need to >upgrade to it for the second WQ feature to work, it would be best if you >do. This version as some changes around how SDR handles request file errors. > >Thats it! The beta release for both the 16 and 32 bit version of WinQuake >and SDR can be download using the following URL's. > >32 bit WinQuake: >ftp://ftp.seismicnet.com/users/psn/software/wq32b1.zip or >ftp://psn.quake.net/software/wq32b1.zip > >16 bit WinQuake: >ftp://ftp.seismicnet.com/users/psn/software/wq16b1.zip or >ftp://psn.quake.net/software/wq16b1.zip > >SDR: >ftp://ftp.seismicnet.com/users/psn/software/sdr24b.zip or >ftp://psn.quake.net/software/sdr24b.zip > >Please use the ftp.seismicnet.com address if possible. This system is on a >higher speed link into the Internet then my 28.8k modem at psn.quake.net. > >The WinQuake zip files only contain the new exe and some dat files. After >unzipping the file all you need to do is copy the files over to your >working WinQuake directory. Make sure you stop the old version before doing >the copy. > >For the SDR release there is a new exe file and all of the current text >files I have for documentation. All you need to do is copy the sdr.exe file >over to your SDR system and restart it. > >If you run into any problems, of have suggestions on the new features (or >old ones) please let me know. > >Thats it, enjoy! > >-Larry Cochrane >Redwood City, PSN > > > > > >_____________________________________________________________________ > >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: Larry Cochrane Subject: Second beta release of WinQuake now ready. Date: Thu, 23 Oct 1997 16:19:36 -0700 Hi, The two bugs that Roger reported (#1 and #2, not sure about #3) in WinQuake have been fixed, thanks Roger for the report. I also added the ability to download report files using FTP. New FTP report files can be entered in the Network Report dialog box as a URL. The URL must start with ftp://. Example: ftp://quake.usgs.gov/pub/www/QUAKES/CURRENT/norcal.list. Please note that on some systems upper and lower case directories and file names must match. I also added horizontal scroll bars to some of the list boxes. The main File Open and the Report dialog boxes now have one. The new beta release for both the 16 and 32 bit version of WinQuake can be download using the following URL's: 32 bit WinQuake: ftp://ftp.seismicnet.com/users/psn/software/wq32b1.zip or ftp://psn.quake.net/software/wq32b1.zip 16 bit WinQuake: ftp://ftp.seismicnet.com/users/psn/software/wq16b1.zip or ftp://psn.quake.net/software/wq16b1.zip Again, please use the ftp.seismicnet.com address if possible. This system is on a higher speed link into the Internet then my 28.8k modem at psn.quake.net. If there are no more bug reports in the next week or so I will go ahead and make a more formal release. So, if you see any problems PLEASE let me know ASAP. Also, if anyone sees any misspelled or wrong words in any of the menu or dialog boxes please let me know. Thats it for now... -Larry Cochrane Redwood City, PSN At 06:52 PM 10/22/97 -0700, Roger Griggs wrote: >Larry, >I have loaded your new versions of sdr and winqk32 and if you have not >already found out from someone else there are some bugs in the winqk32. >1. There is no EXIT on the file menu drop down. >2. In the file menu, below "Print Margins" it seems to automatically add a >list of files and directories (about 9 on mine). As you run the cursor down >the list it automatically loads the contents of the first dir on the list >into the OPEN FILE dialog box in the main window instead of letting you >click on the one you want. >3. I get a timeout error when trying to retreave a replay from winquake. I >will recheck your instructions again to make sure I have not missed >something. I have added the two channel info into the setup and the replay >button is active. > >Roger _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: Second beta release of WQ - right URLs. Date: Thu, 23 Oct 1997 17:58:28 -0700 Oops, the URLs should be: 32 bit WinQuake: ftp://ftp.seismicnet.com/users/psn/software/wq32b2.zip or ftp://psn.quake.net/software/wq32b2.zip 16 bit WinQuake: ftp://ftp.seismicnet.com/users/psn/software/wq16b2.zip or ftp://psn.quake.net/software/wq16b2.zip Sorry about that... -Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: bzimmerman@............ Subject: Alabama? Date: Fri, 24 Oct 1997 09:09:39 -0500 (EST) M 4.9 in Alabama? That is one you don't see every day. We got a nice record here in Pennsylvania. I'll try and post it on my page after class. Are there any reports from the area ? Who knows the geology of the region well enough to explain this one ? Brian Zimmerman _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "John A. Thomas" Subject: Re: Temperature control Date: Fri, 24 Oct 1997 07:16:22 -0700 (PDT) Has anyone attempted to solve the air-current problem in SG type devices by evacuating the air from a container housing the sensor? I have a heavy old bell jar which would nicely fit the device I've been planning. Obviously, you wouldn't want to have vacuum pumps running continuously, so the container would have to hold a decent vacuum for a reasonable amount of time. Any thoughts? John Thomas jathomas@.......... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "James M Hannon" Subject: Re: Temperature control Date: Fri, 24 Oct 1997 09:32:38 -0500 That is exactly where I am headed. My plan is to put each sensor in a piece of copper water pipe and evacuate the pipe. Solder an old metal can IC header into the pipe cap for electrical feed thru. You actually need a very hard vacuum to eliminate all convection currents so even outgassing of the stuff in the vacuum chamber can spoil things. I am hoping that the vacuum combined with the tiny spaces in the instrument will work well enough. Jim Hannon jathomas@.......... on 10/24/97 09:16:22 AM Please respond to psn-l@............. To: psn-l@............. cc: (bcc: James M Hannon/CedarRapids/Collins/Rockwell) Subject: Re: Temperature control Has anyone attempted to solve the air-current problem in SG type devices by evacuating the air from a container housing the sensor? I have a heavy old bell jar which would nicely fit the device I've been planning. Obviously, you wouldn't want to have vacuum pumps running continuously, so the container would have to hold a decent vacuum for a reasonable amount of time. Any thoughts? John Thomas jathomas@.......... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Mike Stickney Subject: Re: Temperature control Date: Fri, 24 Oct 97 08:39:57 MDT John: The old Teledyne-Geotech long period seismometers used in the Large Apeture Seismic Array (LASA) in eastern Montana during the 1970's had sealed housings with a vent through the housing. The vent is threaded, and I'm sure was designed to be attached to a vacuum pump, although I don't know how much of a vacuum they actually operated in. I believe one concern for the vertical seismometers were changes in barimetric pressure that exerted bouyant forces on the mass. -Mike Stickney Montana Bureau of Mines and Geology ====================================== At 07:16 AM 10/24/97 -0700, you wrote: >Has anyone attempted to solve the air-current problem in SG type devices by >evacuating the air from a container housing the sensor? I have a heavy >old bell jar which would nicely fit the device I've been planning. >Obviously, you wouldn't want to have vacuum pumps running continuously, >so the container would have to hold a decent vacuum for a reasonable >amount of time. > >Any thoughts? > >John Thomas >jathomas@.......... > >_____________________________________________________________________ > >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: Robert L Barns <75612.2635@..............> Subject: Re: Temperature control Date: Fri, 24 Oct 1997 13:25:47 -0400 Jim Hannon, = I believe that a hard vac. is not necessary. My reply to John Thomas suggests an experiment that you too can do. Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: Re: Temperature control Date: Fri, 24 Oct 1997 13:25:50 -0400 Mike Stickney, Yes, variations in air pressure around a siesmometer will sh= ow as noise in the output. If the air density changes, the bouyancy effect = on the mass actually changes the effective mass. Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: Re: Temperature control Date: Fri, 24 Oct 1997 13:25:52 -0400 John Thomas, Sure, a vacuum, even not a very good one would solve the air current problem. I would guess that a residual pressure of a few mm would be fin= e. You could get some interesting data by observing the background noise level as you change the pressure. Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Mike Stickney Subject: Re: Temperature control Date: Fri, 24 Oct 97 11:53:08 MDT Bob: I saw this effect very clearly following the 1980 Mt. St. Helens eruption. The long period seismometer at the World Wide Standardized Seismograph Network at Missoula, Montana made a huge, low frequency deflection several hours (I don't recall the transit time precisely) after the eruption. The recording apparently showed passage of a large pressure wave traveling through the atmosphere at sonic speeds. -Mike ====================================== At 01:25 PM 10/24/97 -0400, you wrote: >Mike Stickney, > Yes, variations in air pressure around a siesmometer will show >as noise in the output. If the air density changes, the bouyancy effect on >the mass actually changes the effective mass. >Bob Barns > >_____________________________________________________________________ > >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: Temperature control Date: Fri, 24 Oct 1997 13:12:32 -0500 Robert L Barns wrote: > > Jim Hannon, > I believe that a hard vac. is not necessary. My reply to John Thomas > suggests an experiment that you too can do. > Bob Barns > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L Bob, Yes an experiment is in order. My statement of a hard vacuum is based on what it takes to control convection based heat loss in a TEC cooled CCD cameras for astroimaging and also the operation thermistor vacuum gages that compare convection cooling with radiative cooling to measure the vacuum. These gages will read down to about 10 microns. It maybe that the convection continues down to these levels but the forces generated are too small to affect the sensor. -- Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N 91,39.26W WB0TXL _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Arie Verveer Subject: Seismometer location Date: Sat, 25 Oct 1997 07:46:35 +0800 Hello All, Greetings from one of the silent PSN members and hopefully a soon to be active member. I'm slowly putting together a SG seismometer and wanted to ask a question about locating the seismometers. In my location, I have two outcrops of granite, one is located in the crawl space under the house and the other is located some 20 feet from the house. Assuming its one big lump of granite, do you think it would be pointless to construct a limestone shelter around the outside outcrop and just stick with the easier and more thermally insulated option of locating the device under the house. Your comments and experience would be most helpful. The data acquisition side of the SG seismometer is made up of Larry's 16 bit A/D card , SG amplifier, SG bits and a GPS time source. All of this is connected to a dedicated 486 33Mhz CPU. Locally, we have low-level activity and the very occasional strong quake from a nearby fault, but it should be possible to detect the larger events from Indonesia and across Australia to the Solomon islands. That's assuming my equipment is as sensitive as the seismometers used to gather the data from your distant teleseismic " WinQuake" files. This raises one more question, what do you think is the threshold at which an event should be sent to Larry's mailer? Personally I think, a magnitude 3 or greater for a local event in Australia and all reasonable "WinQuake" data from the overseas events, that is from Perth Western Australia. Any comments? All the best Arie Verveer The Eastern outskirts of Perth :- Western Australia. 116 East -32 South ajbv@............ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: shansen@........ (shansen) Subject: Re: Temperature control Date: Fri, 24 Oct 1997 20:32:50 -0400 (EDT) Convection effects pretty much disappear below about 10 Torr (10mm Hg). In the case of thermal conductivity vacuum gauges (e.g. convection enhanced Pirani gauges - "fancy" versions of thermistor gauges and the like), the gauge operates in convection mode most effectively from about 100 Torr to 1000 Torr (the typical upper limit for commercial gauges) and molecular conduction below about 10 Torr. In the 10 to 100 Torr range (approx) neither mode is very effective and the gauge response flattens out. The effect can be seen quite nicely if you look at the output of a convection Pirani at various pressures while quickly jogging a valve placed between the gauge and the vacuum pump. This introduces a forced convection effect in addition to the natural convection about the gauge's filament and the indication will show a spike. This effect disappears as a pressure of around 10 Torr is approached. In semiconductor vacuum systems, the initial pump down is done slowly to avoid turbulance which will redistribute particles. At 10 Torr, the main valves are opened fully to complete the pumpdown quickly, not a problem since breezes pretty much don't exist. I don't have a citation but there were vacuum clocks (mechanical); evacuated for the same purpose as is being talked about in this thread. Steve Hansen >Robert L Barns wrote: >> >> Jim Hannon, >> I believe that a hard vac. is not necessary. My reply to John Thomas >> suggests an experiment that you too can do. >> Bob Barns >> > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jim Hannon Subject: Re: Temperature control Date: Fri, 24 Oct 1997 20:06:03 -0500 shansen wrote: > > Convection effects pretty much disappear below about 10 Torr (10mm Hg). Thanks Steve, I guess I don't have as much of a problem with the vacuum as I thought. The soldered copper water pipe should hold for quite some time. -- Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N 91,39.26W WB0TXL _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: Alabama? Date: Fri, 24 Oct 1997 20:36:34 -0600 PSN- I got into the office this morning just in time to drive two of our earthquake response team to the airport to fly to Mobile, Alabama with some portable autononmous digital seismographs (PADS). Actually the first info I got about the Alabama event was from the PSN-list which I saw as soon as I arrived at the office, and then I ran into my colleagues busy getting prepared to go. This afternoon when I was talking to some colleagues about the kind of studies of this earthquake that we could do, I was able to show them Frank Cooper's PSN record (Charlie & Terri Thompson's hadn't been posted then). I post info here when we find out what's happening, and maybe, answer some of Brian's questions. -Edward bzimmerman@............ wrote: > > M 4.9 in Alabama? That is one you don't see every day. We got a nice > record here in Pennsylvania. I'll try and post it on my page after class. > Are there any reports from the area ? Who knows the geology of the region > well enough to explain this one ? > > Brian Zimmerman > > _____________________________________________________________________ > > 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: Edward Cranswick Subject: Re: Alabama? Date: Fri, 24 Oct 1997 20:43:42 -0600 PSN- I am sorry that with the rush, I overlooked Bob Lewis's very nice record of the Alabama Earthquake until just now. -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: prewar Subject: Re: Temperature control Date: Sat, 25 Oct 1997 09:28:24 +0100 Jim Hannon wrote: > shansen wrote: > > > > Convection effects pretty much disappear below about 10 Torr (10mm Hg). > > > > I guess I don't have as much of a problem with the vacuum as I thought. > The soldered copper water pipe should hold for quite some time. > -- > Jim Hannon > Hi, If leakage is occuring, cannot the re-exhausting periods be greatly extended by connecting the vacuumed enclosure to a large reservoir, such as an old oxygen cylinder? This can be sited a fair distance away and act as a 'vacuum reservoir'.....excuse wrong terminology? Perhaps all the moving parts of seismos should be STREAMLINED in order to obviate the effects of moving air particles??.....Round section being superior to square etc. Regards. Albert Noble (England) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Arie Verveer Subject: Calibration device Date: Sat, 25 Oct 1997 18:15:15 +0800 Hi All Do you think it would be feasible to place a piezoelectric device under the leveling screws of a "S-G" seismometer and use such a device to calibrate the seismometer. I'm thinking of the "Piezo film kit [A34,808]" that Edmund Scientific sells, or a piezoelectric audible warning device or even a piezo speaker from one of those novelty greeting cards. The seismograph can move beat of happy birthday! But seriously, by feeding the device a low frequency sine wave then it may be possible to calibrate the device's frequency response. Do you think this idea has any merit or should I just forget it. Regards Arie Verveer ajbv@............ Western Australia _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: shansen@........ (shansen) Subject: Re: Temperature control Date: Sat, 25 Oct 1997 09:51:18 -0400 (EDT) >Albert Noble wrote: > >Hi, If leakage is occuring, cannot the re-exhausting periods be greatly >extended by connecting the vacuumed enclosure to a large reservoir, >such as an old oxygen cylinder? This can be sited a fair distance >away and act as a 'vacuum reservoir'.....excuse wrong terminology? >Perhaps all the moving parts of seismos should be STREAMLINED >in order to obviate the effects of moving air particles??.....Round >section being superior to square etc. > Perhaps but you might introduce more complications in terms of the line to the reservoir (e.g. leaks at either end) of outgassing from the walls of the reservoir. If the system is tight with minimal use of elastomeric seals, the pressure should remain in the low Torr range for quite a while. The initial pumpdown should be long to rid the system of adsorbed water. Warming the surfaces will help to outgas residual water. Thereafter, avoid exposure to atmosphere as much as possible to avoid more water coming into the system. Successive pumpdowns to restore vacuum will be much shorter because the system will be relatively clean. Steve Hansen _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "John A. Thomas" Subject: Re: Temperature control Date: Sat, 25 Oct 1997 07:37:32 -0700 (PDT) This is interesting. I was thinking a rotary pump could pull all the vacuum I would need to eliminate significant convection currents. Do you think a diffusion pump would be required? Do you have any calculations on this? John Thomas jathomas@.......... On Fri, 24 Oct 1997, James M Hannon wrote: > > > > > That is exactly where I am headed. My plan is to put each sensor in a > piece of copper water pipe and evacuate the pipe. Solder an old metal can > IC header into the pipe cap for electrical feed thru. You actually need a > very hard vacuum to eliminate all convection currents so even outgassing of > the stuff in the vacuum chamber can spoil things. I am hoping that the > vacuum combined with the tiny spaces in the instrument will work well > enough. > > Jim Hannon _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "John A. Thomas" Subject: Re: Temperature control Date: Sat, 25 Oct 1997 07:41:35 -0700 (PDT) OK, I see where Jim Hannon is coming from. I hope that the forces in a rough vacuum would be insignificant, even though the cooling effects would not be. Still, this raises another question: The power dissapation ratings of electonic components would have to be de-rated, since convective cooling would be much less in the the vacuum. John Thomas jathomas@.......... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jim Hannon Subject: Re: Temperature control Date: Sat, 25 Oct 1997 10:01:10 -0500 John A. Thomas wrote: > > This is interesting. I was thinking a rotary pump could pull all the > vacuum I would need to eliminate significant convection currents. Do you > think a diffusion pump would be required? Do you have any calculations > on this? > > John Thomas > jathomas@.......... > John, >From what Steve Hansen said it looks like a rotary pump will be quite sufficient. That means I can use my refrigeration service pump. The only electrical components that will be in my instrument are the coils for the LVDT and the feedback coil. Only the feedback coil has any potential to dissapate power and it will be completely embedded in an aluminum block which will be good contact with the copper housing. No convection cooling would be possible or necessary. I don't want to put anymore of the electronics in the enclosure because it is easier to fix that way. At work I design electronics that goes in aircraft that fly to 70000 feet. We have to be concerned with convection vs conduction cooling in this environment. Usually we don't worry too much about it and derate all components 50% as a standard practice. This is for everyday electronics. When you get to designing high power stuff you have to pay a little more attention to the details. -- 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: Calibration device Date: Fri, 24 Oct 1997 22:30:09 -0700 Arie I have experimented with this a while back and it works. I used a disk sold by Radio Shack. The problem I encountered is the disk response is velocity dependent and so I was stumped with how to calibrate the disk. One could also make a shaking table with disks(two I would say) and actually shake the sensor as the ground would. The only way I can think to calibrate the disk is with an LVDT or other sensitive desplacement device. I also tried to to use the disk as a sensor itself but they have such a high natural frequency(Radio Shack has a response curve shown with theirs) that I couldn't get the gain or damping correct. Let me know what you find out.I think they are compact and simple if the electronics could be worked out. Barry Arie Verveer wrote: > > Hi All > > Do you think it would be feasible to place a piezoelectric device under the leveling > screws of a "S-G" seismometer and use such a device to calibrate the seismometer. > > I'm thinking of the "Piezo film kit [A34,808]" that Edmund Scientific sells, or > a piezoelectric audible warning device or even a piezo speaker from one of those > novelty greeting cards. The seismograph can move beat of happy birthday! > > But seriously, by feeding the device a low frequency sine wave then it may be > possible to calibrate the device's frequency response. > > Do you think this idea has any merit or should I just forget it. > > Regards > > Arie Verveer > > ajbv@............ > Western Australia > > _____________________________________________________________________ > > 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: System output Date: Fri, 24 Oct 1997 22:40:30 -0700 Hi All I have been having an elecrtical problem for awhile and was wondering if anyone else experiences this also or could shed some light one the solution. When a large event is recorded on my system and the signal is clipped, why do I not get full scale count output with the computer(ie 4096 for a 12 bit system)? I get less than 2000. I have put +5 to -5 vts into the A/D and get the proper output so I know it's not the A/D. My electronics path from the sensor has gains all above one. It seems once and amp reaches the max all the others after would also. Any ideas. I wouldn't care except I think it's affecting my dynamic range. Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: 'Quake prediction? Date: Sat, 25 Oct 1997 13:57:23 -0400 Hi gang, The enormous complexities inherent in predicting earthquakes are discussed in a recent item in Science magazine, Oct. 17, vol 278, pp 487-490. This is two critiques of an article in Science vol 275, 1997, p 1616 by= RJ Geller et. al. who concluded that prediction would probably never be possible. A response by Geller et. al. is included. Extensive lists of references are provided if you are inclined to dig further. If your local library does not have the magazine, it can probably get y= ou a photocopy. Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: frankcnd@.......... (Frank Condon) Subject: Re: 'Quake prediction? Date: Sat, 25 Oct 1997 13:05:20 -0700 (PDT) >Hi gang, > The enormous complexities inherent in predicting earthquakes are >discussed in a recent item in Science magazine, Oct. 17, vol 278, pp >487-490. > This is two critiques of an article in Science vol 275, 1997, p 1616 by >RJ Geller et. al. who concluded that prediction would probably never be >possible. A response by Geller et. al. is included. Extensive lists of >references are provided if you are inclined to dig further. > If your local library does not have the magazine, it can probably get you >a photocopy. >Bob Barns > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > Hi Bob: Without spilling the beans about the entire article, what is the main reason given for not being able to predict an earthquake? Does this article give out any Web references for us to peruse that are about seismic predicting? Thanks, Frank mail to: frankcnd@.......... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: shammon1@............. Subject: Re: BBS Phone numbers / Keep them or dump them? Date: Sat, 25 Oct 1997 20:37:27 -0700 shammon1@............. wrote: > > Hi Larry-- You bring up a good question. I have been wondering if the BBS > still brings value to the group. I moved the San Jose system from an old > AT to a 486-33 because the old 100M HDD was reaching end of life and the > bearings sounded like they were going to fall out. Over the last month I > have had it running in my workroom (it's wonderful when kids grow up and > leave home... ) and I switched it off last weekend. Your the first to > speakup. It's now 8:00 PM on a Sat night and I just put it back on-line. > > So, my question to the group is, is the BBS in San Jose of any value to > you given the WWW? Should I keep the BBS's on-line or pull the plug? If > you want to dial-in and look around the phone number is 408-226-0675. > > Regards, Steve Hammond BBS Sysop San Jose, California > > Larry Cochrane wrote: > > > > Hi There, > > > > I was wondering if your BBSs are still running? I tried calling San Jose > > and Pasadena and both are not answering. I did not try Charles. Since some > > of us have Web pages listing these numbers we should make sure that they > > are still active. So please let me know if your system is still up and > > running, or off line, so I can update my web page. > > > > Thanks, > > > > -Larry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: Seismometer location Date: Sat, 25 Oct 1997 21:31:14 -0700 At 07:46 AM 10/25/97 +0800, Arie Verveer wrote: > >Hello All, > >Greetings from one of the silent PSN members and hopefully a >soon to be active member. > >I'm slowly putting together a SG seismometer and wanted to ask >a question about locating the seismometers. In my location, I >have two outcrops of granite, one is located in the crawl space >under the house and the other is located some 20 feet from the house. >Assuming its one big lump of granite, do you think it would be >pointless to construct a limestone shelter around the outside outcrop >and just stick with the easier and more thermally insulated option of >locating the device under the house. > >Your comments and experience would be most helpful. I would first try locating the sensor under the house. This would be a lot easier etc... If you get too much noise from the house moving, or from people moving in it, I would then go for the outside location. > >The data acquisition side of the SG seismometer is made up of Larry's >16 bit A/D card , SG amplifier, SG bits and a GPS time source. >All of this is connected to a dedicated 486 33Mhz CPU. > >Locally, we have low-level activity and the very occasional strong >quake from a nearby fault, but it should be possible to detect the larger >events from Indonesia and across Australia to the Solomon islands. That's >assuming my equipment is as sensitive as the seismometers used to gather >the data from your distant teleseismic " WinQuake" files. Its hard to say... You should be able to receive a mid or high M7 anywhere on the earth. Depending on the distances, you may only get the low frequency surface waves, but you should be able to detect it. > >This raises one more question, what do you think is the threshold at >which an event should be sent to Larry's mailer? > >Personally I think, a magnitude 3 or greater for a local event in Australia >and all reasonable "WinQuake" data from the overseas events, that is from >Perth Western Australia. Any comments? > I would say any local event where you get a clear P and S wave. Some of the smaller local events are more interesting then the bigger ones. -Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Karl Cunningham Subject: Re: System output Date: Sat, 25 Oct 1997 22:43:24 -0700 Barry -- Here is a possible scenario... For purposes of talking, say you have a circuit with two stages -- the first stage is an amplifier and the second a low-pass filter. Suppose the first stage is outputting a full-scale signal of a frequency higher than the low-pass filter's cutoff. When the first stage reaches full scale, suppose the second stage is only at half-scale due to the filter. Then, the signal at the first stage peaks and starts back down and the second stage may not have had a chance to get much over half scale. With a little more signal, the first stage could even be clipping and the second stage not even near full scale. Does this sound plausible? There may be other explanations too. Karl Cunningham La Mesa, CA. PSN Station #40 karlc@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: System output Date: Sat, 25 Oct 1997 20:18:28 -0700 Karl It seems plausible. Most of my low pass filters are set for 10hz. I'll have to check the FFT for the specific events to see how close to 10hz the signal gets. Barry Karl Cunningham wrote: > > Barry -- > > Here is a possible scenario... > > For purposes of talking, say you have a circuit with two stages -- the > first stage is an amplifier and the second a low-pass filter. Suppose the > first stage is outputting a full-scale signal of a frequency higher than > the low-pass filter's cutoff. When the first stage reaches full scale, > suppose the second stage is only at half-scale due to the filter. Then, > the signal at the first stage peaks and starts back down and the second > stage may not have had a chance to get much over half scale. With a little > more signal, the first stage could even be clipping and the second stage > not even near full scale. > > Does this sound plausible? There may be other explanations too. > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: SG output Date: Sat, 25 Oct 1997 20:27:31 -0700 Larry I have been playing around with my SG sensor. The recent Trinidad event only showed low frequency output. You have mentioned about taking two outputs,one before and one after the integrator and recording them. I think I'm going to try putting a summing amp after and adding the two. Because the integrator is inverting I will change the sign of the signal so the two signals have the same sign. What do you think? Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: GeE777@....... Subject: Re: System output Date: Sun, 26 Oct 1997 10:25:58 -0500 (EST) In a message dated 97-10-26 01:44:50 EDT, karlc@....... writes: << When the first stage reaches full scale, suppose the second stage is only at half-scale due to the filter. >> I f I remember my electronics studies, when you clip a signal in a linear amplofier, you make higher frequencies, double or triple, depending on the type of distortion. Your second stage, the low pass filter, will attenuate these distorted signals which now are higher frequency. All stages of a linear amplifier must not be driven to distortion. to preserve the signal as true as possible. Could you put your low pass filter as the first stage? George Erich GeE777@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: System output Date: Sat, 25 Oct 1997 21:01:55 -0700 George That's a thought. I know square waves have high frequency components due to the corners. I wasn't thinking of a clipped wave as square before. I'll check how my filters and amps are arranged Barry GeE777@....... wrote: > > In a message dated 97-10-26 01:44:50 EDT, karlc@....... writes: > > << When the first stage reaches full scale, > suppose the second stage is only at half-scale due to the filter. >> > > I f I remember my electronics studies, when you clip a signal in a linear > amplofier, you make higher frequencies, double or triple, depending on the > type of distortion. Your second stage, the low pass filter, will attenuate > these distorted signals which now are higher frequency. All stages of a > linear amplifier must not be driven to distortion. to preserve the signal as > true as possible. Could you put your low pass filter as the first stage? > > George Erich > GeE777@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: Calibration device Date: Sun, 26 Oct 1997 13:43:43 -0500 Arie, Using a piezoelectric transducer might well work for getting the frequency response of a seismometer. However, I don't see any way to use this to get a velocity calibration in= common units such as cm/sec. since you will not know how far the transduc= er acutally moves the seismometer. Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: Magnetic bridges Date: Sun, 26 Oct 1997 13:43:52 -0500 Hi gang, I've observed an amusing phenom which may reduce the tedium of your dai= ly commute in the car. I have an automobile compass mounted on the dash (often useful in the wil= ds of north Jersey). It is just an ordinary undamped compass--not a flux ga= te or anything fancy. = I frequently get a sudden deflection when passing over each end of a bridge at normal speeds. These are someimes violent--the pointer sometim= es goes around a full 360 deg. or so. By bridge, I mean the minor ones over= a dip in the territory or a creek. A big bridge such as the Geo. Washingto= n is not required. The blips usually but not always occur only at the ends of the bridge--the compass usually points in the proper direction while between the two ends. A long bridge sometimes has an additional blip or two between the ends. I have never seen a blip when passing under an overpass. I guess this = is consistent with the observation of normal deflection in the center of a bridge since going under an overpass is away from its ends. I have not done the obvious experiment of walking over a brige with compass in hand to observe the static deviations. Since I'm not the outdoors sort, I'll leave that to one of you. I postulate two possible sources for the bridges' magnetism: 1. The steel in the bridge cools thru the Neel temperature in the earth's magnet= ic field during manufacture or 2. the steel is magnetized by the hammering when rivets are used to fasten the whole thing together. I suppose that = is possible that the higher permeability (compared to normal road materials)= of the steel simply concentrates the earth's field at the ends. I have n= ot tried to correlate the size of the effect with the orientation of the bridge. Bob Barns = _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jim Hannon Subject: Re: Magnetic bridges Date: Sun, 26 Oct 1997 13:15:18 -0600 Robert L Barns wrote: > I postulate two possible sources for the bridges' magnetism: 1. The > steel in the bridge cools thru the Neel temperature in the earth's magnetic > field during manufacture or 2. the steel is magnetized by the hammering > when rivets are used to fasten the whole thing together. I suppose that is > possible that the higher permeability (compared to normal road materials) > of the steel simply concentrates the earth's field at the ends. I have not > tried to correlate the size of the effect with the orientation of the > bridge. > Bob Barns A couple of comments. Number 1 is unlikely to cause the effect you are seeing as the pieces of steel would all be oriented diffenently in the bridge than when they were made and tend to cancel out. Both number 2 and the concetration effect are the likely causes. Ships use magnetic compases and the ship itself causes both the concentration effect and the being magnetized effect. To compensate the compass for the concentration effect there are two large iron balls located on each side of the compass. These are adjusted so that the combined magnetic effect of the balls and the ship are equal in all directions. The being magnetized is compensated for by a number of coils arranged around the compass. The current in the coils is adjusted to cancel out the ships field. An additional complication is introduced when the anti magnetic mines coils are turned on. These huge coils cancel out the overall magnetic field of the entire ship so as not to set off magnetic mines. When a ship goes into drydock for repairs it is usually necessary to recalibrate the whole system as all the pounding and sandblasting on the hull will change the field of the ship. -- Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N 91,39.26W WB0TXL _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: Re: Seismometer location Date: Sun, 26 Oct 1997 14:32:26 -0500 Hi gang, My results suggest that Larry may be unduly pessimistic about distant 'quakes. Here is the list of my 6 most distant 'quakes (out of about 130= ): Where 1997 UTC M = miles sig/noise E. New Guinea 4/5 12:23:30 6.1 8950 2 N. Sumatera 8/20 7:15:17 6 9253 5 Indonesia 6/24 23:4:53 6.1 9380 1.5 Coast. Cent. Chile 7/6 9:54:3 6.5 9800 120 W. Australia 8/10 9:20:33 6 10451 6 Mid Indian Ridge 8/20 13:51:15 6.4 11120 10 The mid Indian ridge of 8/20 was 161 deg. away--just about as far as possible. This is with an ordinary Lehman. The only improvement over the usual i= s that I have a 6-pole active low-pass filter with a knee at 0.08 Hz and th= e Lehman usually has a 30 sec. period. I normally do not do any FFT filtering which would improve the S/N somewhat. So I think that I can see a 'quake if it is about 6 or great= er unless it is off the ends of the Lehman (in the sensitivity nulls). Of course, the minimum detectable signal is usually set by your local seismi= c noise level. = Bob Barns (in seismically deprived New Jersey) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert Avakian Subject: Re: Magnetic bridges Date: Sun, 26 Oct 1997 15:39:05 -0800 I can think of other possibilities. The ends of the bridge may be the sites of a spontaneous potential difference (SP) with the soil, which could produce an observasble electromagnetic field. Also, any body with an acceptable magnetic susceptability lying in the earth's field will modify that field due to several factors. This is why magnetic surveying can detect faults in bedorck at depth. Prehaps the ends of the bridge are the sites of magnet signal. In any case, it would seem that the car itslef is the prime culprit. Aany movement through a field would induce a seconadry field w/i the car which would then jump the compass. If so, the effect would be less in a fibreglass car such as a 'vette. A special note to desparate parents of science students. This looks like a SUPER science fair project!!! Bob Avakian Jim Hannon wrote: > > Robert L Barns wrote: > > I postulate two possible sources for the bridges' magnetism: 1. The > > steel in the bridge cools thru the Neel temperature in the earth's magnetic > > field during manufacture or 2. the steel is magnetized by the hammering > > when rivets are used to fasten the whole thing together. I suppose that is > > possible that the higher permeability (compared to normal road materials) > > of the steel simply concentrates the earth's field at the ends. I have not > > tried to correlate the size of the effect with the orientation of the > > bridge. > > Bob Barns > > A couple of comments. Number 1 is unlikely to cause the effect you are > seeing as the pieces of steel would all be oriented diffenently in the > bridge than when they were made and tend to cancel out. Both number 2 > and the concetration effect are the likely causes. Ships use magnetic > compases and the ship itself causes both the concentration effect and > the being magnetized effect. To compensate the compass for the > concentration effect there are two large iron balls located on each side > of the compass. These are adjusted so that the combined magnetic effect > of the balls and the ship are equal in all directions. The being > magnetized is compensated for by a number of coils arranged around the > compass. The current in the coils is adjusted to cancel out the ships > field. An additional complication is introduced when the anti magnetic > mines coils are turned on. These huge coils cancel out the overall > magnetic field of the entire ship so as not to set off magnetic mines. > When a ship goes into drydock for repairs it is usually necessary to > recalibrate the whole system as all the pounding and sandblasting on the > hull will change the field of the ship. > -- > Jim Hannon > http://soli.inav.net/~jmhannon/ > 42,11.90N 91,39.26W > WB0TXL > > _____________________________________________________________________ > > 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: GeE777@....... Subject: Re: Calibration device Date: Sun, 26 Oct 1997 19:04:14 -0500 (EST) Hi All, I sent a post on this before. However, it may not work with the seismometers you are using. I know it works with the seismometers used in seismic exploration. Apply a DC voltage to the coil to displace it to the end of the coil travel space, a known distance. Remove the voltage, and the resultant wavelet from the geophone is- 1) The DC voltage removed. 2) A voltage spike caused by the magnetic field collapsing around the coil when the DC voltage is removed. 3) A wavelet generated by the coil moving to the normal resting place. This wavelet, 3), is the step function response of the geophone when the coil comes to rest. A second derivative of this wavelet is the geophone response to a spike. If you can measure the distance you offset the coil with the DC voltage that was applied to the coil, you should be able to calculate the output sensitivity of your geophone in volts/in/sec or volts/cm/sec George Erich GeE777@....... n a message dated 97-10-26 13:49:12 EST, 75612.2635@.............. writes: << Using a piezoelectric transducer might well work for getting the frequency response of a seismometer. However, I don't see any way to use this to get a velocity calibration in common units such as cm/sec. since you will not know how far the transducer acutally moves the seismometer. Bob Barns >> _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: Temperature control Date: Sun, 26 Oct 1997 18:17:45 -0700 PSN- I figured that since there was so much discussion of temperature that I should put my two cents in, even if it weren't very relevant. In 1982, the Canadian Earth Physics Branch (Ottawa; the Bob Wetmiller was the chief of the field investigation) asked us, USGS Menlo Park, to help chase aftershocks of the 9 January 1982 magnitude 5.8 (MbLg) Miramichi Earthquake off in the boonies of New Brunswick (SE Canada just to the NE of the state of Maine) and loan them some portable autonomous digital seismographs (PADS), and Gene Sembera and I were part of that loan. The temperature was -30 C (~20 F) and the winds blew at 50 kph (~30 mph). The PADS recorders (3-channel Sprengnether DR-100s: one of the first commercial PADSs) were located in vacant huts in the epicentral area that we heated with kerosene heaters to a toasty 0 C and the sensors were installed outside, frozen to the ground and covered with snow. I decided to deploy two DR-100 at each of two sites, one equipped with a 3-component 2-Hz S6000 geophone (velocity transducer) and the other with an 3-component FBA (acceleration transducer), and the signals were recorded at a sample rate of 200 sps with 6-pole low-pass anti-alising filters at 50 Hz). The peak values of the velocity records (seismograms) and integrated acceleration records of the same events recorded by the co-sited PADS differed at most by 10%. The corresponding spectral ratios of the integrated acceleration to the velocity showed a maximum difference of ~3 dB (most frequencies were different by less than 10%) over the frequency band 2-50 Hz. Therefore, because the two sensors at each site recorded different orders of motion (velocity and acceleration) but produced comparable records, we were confident that the instruments were working reliably and were not seriously affected by the cold. -Edward Larry Cochrane wrote: > > At 09:59 AM 10/17/97 -0400, Robert Barns wrote: > >Hi gang, > [snip] > > Since a Shackleford-Gunderson operates part of the circuitry at DC, it > >might not be as immune to wide temperature swings. Maybe Larry can give us > >his thoughts on this. > >Bob Barns > > > > Do to its size I think the Lehman would be more sensitive to temperature > changes. Living in California reduces the temperature extremes (thank god!) > so I can't say for sure how my Lehman and SG sensor would do in > temperatures below 0 F or above 100F. I don't think the electronics will be > a problem, because I use high quality op-amps etc. The SG sensor is > extremely sensitive to air currents inside the box that covers the senor. > This can be fix by filling the inside of the box with foam rubber so that > it occupies as much of the free space as possible without touching the > sensor itself. > > -Larry Cochrane > Redwood City, PSN > > _____________________________________________________________________ > > 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 Caruso Subject: Re: Magnetic bridges Date: Sun, 26 Oct 1997 20:44:41 -0500 (EST) When dropped or hammered, do not magnets loose their strength? But then when they are heated the become magnetic? STEPHEN CARUSO CET KB8UGH "Coincidence is a shortsighted mental delusion" _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Stephen Caruso Subject: Re: Calibration device Date: Sun, 26 Oct 1997 20:47:03 -0500 (EST) What about a plain speaker w/low freq sent by function generator. Build your own from Jameco for $20. STEPHEN CARUSO CET KB8UGH "Coincidence is a shortsighted mental delusion" _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jim Hannon Subject: Re: Magnetic bridges Date: Sun, 26 Oct 1997 19:58:24 -0600 Stephen Caruso wrote: > > When dropped or hammered, do not magnets loose their strength? > But then when they are heated the become magnetic? > A permanent magnet can be destroyed by both heating or hammering. Both actions have similar effects, kind of like sirring things up. However if you were either to heat and then cool or hammer a magnet in the presence of a strong external magnetic field the magnet would tend to take on the applied field. This is what happens when hammering a ship or bridge except the external field is not so strong (ther earth's field). -- Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N 91,39.26W WB0TXL _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "David A. Nelson" Subject: Snow Date: Mon, 27 Oct 1997 17:22:49 +1200 Ed, hope all is well with you in Colorado Ed, the snow storms look pretty severe on the TV news, in your and surrounding states. 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: "David A. Nelson" Subject: reasonable Sth Pacific quake Date: Mon, 27 Oct 1997 22:41:57 +1200 0937 utc 3 min s-p from dunedin NZ, not large amp ~m6-6.5 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: ACole65464@....... Subject: Re: Temperature controller Date: Mon, 27 Oct 1997 23:40:10 -0500 (EST) Hi PSN, Sorry to be getting into this thread a little late but could I add my 2 cents worth as well? A technician at NEIC who has worked on Streckeisen STS-1 vertical seismometers that are enclosed in a bell jar answered my questions as to how good a vacuum to use, and how long will the vacuum last. First he told me that the seismometer rests on a flat pyrex (he thinks) glass plate that is bonded to the supporting cement slab. A flat silicone rubber gasket lays on the plate and the bottom lip of the glass bell jar rests on top of the gasket. Vacuum grease is applied to both sides of the gasket to ensure an air tight seal between rubber and glass. A stop cock at the top of the bell jar is all that seals the top end after it is evacuated. He could not say how good the vacuum was but said it was not all that great and he had to use a vacuum pump supplied with the seismometer. I asked how frequently did the bell jar had to be pumped down and he said only after servicing etc did the bell jar get pumped down and not again until the jar was opened again, maybe a year or so later. I have been fortunate enough to closely examine an old Sprengnether 30 second vertical velocity seismometer that was once used in the WWSSN. It was not evacuated in any way, it had a simple 16 ga steel cover that went over the instrument. The cover is about 12" wide x 24" long x 24" high with simple embossed ribs running diagonally from corner to corner across the sides for extra rigidity. It had welded corners and the few fittings that protruded through the sides had rubber gaskets to seal out the air. Rubber gaskets were also fitted around the items mounted to the one piece cast metal (iron?) base. The sheetmetal cover was pulled down onto the base with 6 "J" bolts, 3 down each long side of the instrument. A 1/4" thick rubber gasket went between the the cover and base for the air tight seal. This system was apparently good enough for many years of acceptable recording quality. The seismometer was installed in a WWSSN vault that had passive heating panels mounted on the ceiling with the room heated to a toasty 65 deg F. The walls were lined with 2" thick sytrofoam insulation. That was their answer to controlling convection currents. Over each instrument also was a plywood box internally lined with 3" fiber glass insulation for additional help with a 3" gap between insulation and seismometer. I hope this gives some of you ideas as to what limits you need to go to. Bye for now, Allan Coleman, Seattle _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Event Date: Mon, 27 Oct 1997 13:06:59 -0800 All I picked up a teleseismic event on 10/28 @ 06:15:06 @ 6637k from Grass Valley. No info from USGS yet. Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "David A. Nelson" Subject: Re: Event Date: Tue, 28 Oct 1997 20:18:26 +1200 Barry, an initial report said Mb5.8 Peru - Bolivia border but after seeing a few professional seismograms from around the world Tony (in Hawaii) and I tend to believe it to be somewhat bigger it totally dwarfs the Mb5.5 from the Kermadecs last nite Dave At 01:06 PM 10/27/97 -0800, you wrote: >All > I picked up a teleseismic event on 10/28 @ 06:15:06 @ 6637k from >Grass Valley. No info from USGS yet. > Barry > >_____________________________________________________________________ > >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: "David A. Nelson" Subject: Re: Event UPDATE Date: Tue, 28 Oct 1997 20:25:47 +1200 Hi all 97/10/28 06:15:18 4.32S 76.63W 124.5 6.5Mb A NORTHERN PERU Dave At 01:06 PM 10/27/97 -0800, you wrote: >All > I picked up a teleseismic event on 10/28 @ 06:15:06 @ 6637k from >Grass Valley. No info from USGS yet. > Barry > 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: Charlie Rond Subject: Re: Event Date: Tue, 28 Oct 1997 03:42:41 -0600 Barry, > I picked up a teleseismic event on 10/28 @ 06:15:06 @ 6637k from >Grass Valley. No info from USGS yet. Got it here. 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: "David A. Nelson" Subject: Event UPDATE #2 Date: Tue, 28 Oct 1997 20:58:15 +1200 Hi all, Here's the data from Caltech, NOTE: they use Mw Dave Subject: CMT Mw=7.2 NORTHERN PERU General region : NORTHERN PERU surface waves (3.0,3.5,7,7.5 mHz) Stations used : COR CTAO KONO PAB TUC Origin time: 1997 301 6 15 18 Original location (lat,lon,depth) : -4.30000 -76.6000 125 Moment tensor (x1.e26 dyncm) : Mrr : -7.240666 Mtt : 1.065872 Mff : 6.174794 Mrt : -0.871906 Mrf : 1.474340 Mtf : -2.157320 T-axis: moment= 7.161 plunge= 6.676 azimuth= 249.605 N-axis: moment= 0.289 plunge= 2.249 azimuth= 159.341 P-axis: moment= -7.450 plunge= 82.952 azimuth= 50.822 best double couple: Mo= 7.306(x1.e26 dyncm) Mw=7.2 tau= 10.7 nodal planes (strike/dip/slip): 342.18/ 38.37/-86.38 157.57/ 51.72/-92.87 Centroid location : -4.554 -75.832 103.724 Centroid time : 13.981 Variance reduction (%) : 87 o*********** ****ooooooo -**** ***oo oooo ---*** **- o ooo -----** **-- oo oo -----** *---- o ooo------* *----- o oo------* **----- o o -----** *-------o oo -----* **-------oo P o -----** **--------o + o ----** **--------oo o ----** *---------oo o ----* **T--------oo o ---** *----------oo oo ---* *----------oo o --* **---------ooo oo -** **----------ooo oo ** ***-------- oooo oo*** ****------ ooo**** ***********o 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: prewar Subject: Formula for horizontal pendulums. Date: Tue, 28 Oct 1997 14:33:35 +0000 Hello everyone, For anyone who is designing/building a SIMPLE horizontal pendulum, ( without using any electronic magic to alter its swing rate), you may like to have my formula linking swing rate/beam length/vertical offset. Knowing any two of these, allows one to calculate the third. (FORGIVE, if this has appeared before, but I haven't come across it in the archives.)...Yes, I'm STILL reading them !! DEFINITIONS. The vertical offset is the horizontal distance from the pivot POINT to the top termination of the suspension wire, when looking SIDEWAYS at the seismograph. (The top termination always being slightly 'forward' of the point, by this vertical offset amount as you all know. ) The beam length, measured from beam pivot point to suspension point, and the vertical offset are both measured in INCHES. T is the swing periodicity in seconds (that's swing to AND fro). It is based on the geometry of hor. pendulums, PLUS the formula for pendulum simple harmonic motion. It ASSUMES that the angle between beam and tension wire is 45 degree. (use tan of this angle for other configurations). (If anyone wishes to know how I derived above, contact me, as don't wish to clutter PSN with over large letters!). It also assumes that you are on the EARTH !! Moon dwellers etc. must revamp for different gravity acceleration figures ( 772.8 is x2 acceleration due to earth gravity, in inches/sec/sec) 2 beam length Vertical offset = ______________________ 2 ( T / 2 pi ) x 772 .. 8 ..................................................................................................... For example, if your beam length is 30" and you wish to have a swing periodicity of, say 20 seconds, the vertical offset in this case calculates out to something just over 1/8th. inch For 40 secs the vert. offset comes down to 1/32 inch, and so on. You can see from above that for long swing periods, particularly with short pendulum beams, the ENGINEERING standards MUST be fine, in order to achieve the smaller offset stable values necessary. The square of the beam length and square of T, are your enemies in this respect. The experienced builders out there will NOT need reminding of this! If any one has other formula for beams I would be VERY interested in seeing them. What about VERTICAL spring periodicity, when anchored part way along beams in vertical pendulums? Haven't been able to puzzle this out yet...the percentage stretch of the spring and ratio of beam length to anchor point to knife edge is involved. Regards, Albert Noble (England). _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: prewar Subject: Formula for horizontal pendulums. Date: Tue, 28 Oct 1997 14:44:40 +0000 Hello everyone (again), Sorry for rotten layout...here's improvement... 2 beam length Vertical offset = _____________________ 2 ( T / 2 pi ) x 772.8 Regards, Albert Noble (England). _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Walt Williams" Subject: SETI hdwe: stabilizing crystal oscillators Date: Tue, 28 Oct 1997 12:26:32 +0000 Hello All, An interesting thread in the PSN-L has been ongoing regarding thermal stabilization. I have seen other similar posts in the PSN-L, so I thought this might be relevant and of interest to others in the PSN-L. This was posted in the SETI-L reflector list. Dr. Shuch has kindly granted permission to cross-post this to the PSN-L. Best Regards, Walt Williams, 97.10.28 dfheli@.............. Woodland Hills, California USA ------- Forwarded Message Follows ------- Date: Tue, 28 Oct 1997 11:41:09 -0500 To: seti@....... From: "Dr. H. Paul Shuch" Subject: SETI hdwe: stabilizing crystal oscillators Cc: rcf@.............. Anyone who has built a crystal controlled oscillator (for use in a local oscillator chain or weak signal source) has probably noticed frequency drift as a function of temperature. The usual solution is to place the crystal in a proportionally controlled oven -- an expensive solution to be sure. At Microwave Update last weekend, Steve Kostro of Down East Microwave suggested an inexpensive solution: use a positive temperature coefficient (PTC) thermistor for simultaneous heat and regulation. One end of a 60 ohm (@ room temperature) PTC is physically soldered to the can of an HC-18/U crystal, which is itself grounded. The other end goes to +9 or +12 VDC. The thermistor draws (initially) about 200 mA of current, heats the crystal can up to about +60C, its resistance goes way up and it stops drawing current. As it cools a little, its resistance goes back down somewhat, it starts drawing some current, and heats up again. Makes for a self-regulating oven at about 40 degrees above ambient temperature! This really stabilizes the crystal frequency. I just tried it, and it works great. ----------------------------------------------------------------- H. Paul Shuch, Ph.D. Executive Director, The SETI League, Inc. 433 Liberty Street, PO Box 555, Little Ferry NJ 07643 USA voice (201) 641-1770; fax (201) 641-1771; URL http://www.setileague.org/ email work: n6tx@............... home: drseti@........... "We Know We're Not Alone!" _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Robert L. Thomasson" <102073.3346@..............> Subject: SETI hdwe: stabilizing crystal oscillators Date: Tue, 28 Oct 1997 16:22:54 -0500 <> Pardon my ignorance, but what is SETI? Society for Extra Terrestial Investigation or something similar? Sounds kind of interesting. Regards, Bob Thomasson _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Walt Williams" Subject: FWD[2] SETI hdwe: stabilizing crystal oscillators Date: Tue, 28 Oct 1997 17:09:45 +0000 Hello Bob Thomasson, >------- Forwarded Message Follows ------- >Date: Tue, 28 Oct 1997 16:22:54 -0500 >From: "Robert L. Thomasson" <102073.3346@..............> >Subject: (Fwd) SETI hdwe: stabilizing crystal oscillators To: > PSN-L Mailing List Reply-to: >PSN-L Mailing List ><Dr. Shuch has kindly granted permission to cross-post this to the >PSN-L.>> >Pardon my ignorance, but what is SETI? Society for Extra Terrestial >Investigation or something similar? Sounds kind of interesting. >Regards, Bob Thomasson This is off topic, and I will keep this brief. acronym decodes: SETI League := Search for ExtraTerrestrial Intelligence League I understand this is a group of amateur and professional radio-astronomers, whose constituent member set are mostly ham radio operators. Their goal is locating technical extraterrestrial civilizations by looking for their high frequency energy emmissions using inexpensive 'amateur-home-brew' and or commercial radio equipment implemented for that task. Though there are no official ties to the (previously NASA funded) orthodox scientific SETI organization, some SETI-League members are affiliated with both organizations. I am not a representative of this group. Best Regards, Walt Williams, 97.10.28 dfheli@.............. Woodland Hills, California USA =============================== Date sent: Tue, 28 Oct 1997 15:05:39 -0500 To: "Walt Williams" From: "Dr. H. Paul Shuch" Subject: Re: Cross Posting Copies to: rcf@.............. At 11:49 AM 10/28/97 +0000, you wrote: >Hello Dr. Paul Shuch, > >I am a member of another reflector list: the "Public Seismic >Network-List". In this list there has been a discussion regarding >thermal stabilization. I was wondering if I might cross post your >interesting 'crystal-stabilization' post to that list? I have no objection whatever, Walt. Please do include a pointer to The SETI League web site, . Thanks. ----------------------------------------------------------------- H. Paul Shuch, Ph.D. Executive Director, The SETI League, Inc. 433 Liberty Street, PO Box 555, Little Ferry NJ 07643 USA voice (201) 641-1770; fax (201) 641-1771; URL http://www.setileague.org/ email work: n6tx@............... home: drseti@........... "We Know We're Not Alone!" _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert Avakian Subject: Re: (Fwd) SETI hdwe: stabilizing crystal oscillators Date: Tue, 28 Oct 1997 23:22:50 -0800 Search for Extra Terrestrial Intelligence. I guess some folks have given up on finding any here on earth :> Robert L. Thomasson wrote: > > < Dr. Shuch has kindly granted permission to cross-post this to the > PSN-L.>> > > Pardon my ignorance, but what is SETI? Society for Extra Terrestial > Investigation or something similar? Sounds kind of interesting. > > Regards, Bob Thomasson > > _____________________________________________________________________ > > 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: PSN map updates Date: Thu, 30 Oct 1997 00:49:42 +1200 hi ya all, two new additions to the USA map one is a replacement 1) Welcome Al Allworth near Gold Beach on the south coast of Oregon 2) and welcome David Wolny who has a system running at Mesa State College, Grand Jnct, Colorado Note:.... David replaces Frank Anderson on the map and in the database as he (Frank) is no longer in Grand Jnct and his e-mail address has been terminated. With these alterations, we have broken the big 50 with 51 stations now logged WOW!! there will be two new Australian stations on the world map soon.... one from Perth, W. Aust. and one from NSW once I get a bit more station data the dots will appear cheers from the deep south 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: "David A. Nelson" Subject: another addition Date: Thu, 30 Oct 1997 02:11:36 +1200 hi again, on the Californian map there is now a new dot below Steve Hammond it is the site of the Almaden County School, Sth San Jose. Ted Blank looks after this system. Sorry Ted, Your school site has been in the database for a while just haven't had time to do the map update. with a much higher resolution map of Calif. now available from the USGS.... I will soon be upgrading the Calif. map to get rid of its chunky look.... That will keep the peace in the "Sunshine State" 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: Greg Lyzenga Subject: Re: another addition Date: Wed, 29 Oct 1997 09:02:03 -0800 Dave Nelson wrote: >That will keep the peace in the "Sunshine State" > Oops! That may not keep the peace among Californians, since Florida is the "Sunshine State"! :-) California claims to be the "Golden State". We need to keep this list technically accurate after all! - Greg Gregory A. Lyzenga, Dept. of Physics, Harvey Mudd College -> lyzenga@................. <- _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Dewayne (n0ssy) and Linda (n0uqf) Hill" Subject: Can a sound card be used as an A/D? Date: Wed, 29 Oct 1997 12:06:16 -0700 Hi to all, I have been interested in setting up a seismeter in my house for sometime. I have aquired some large magnets (from and IBM 3380 disk drive.) Now I have to get some type of A/D card and software for my PC. With no knowledge as to the inter-workings of the Sound Blaster sound card or the software to support it and my general knowledge of electornics is seem to me that all a sound card is is an A/D converter (it has an output - spearker out and an input - Mic in.) I am want to know if anyone has tried to connect the output from a senseing coil straight into a sound card. Can this type of connection be made to work? Any info would be helpful. Regards, Dewayne Hill _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: jim cristiano Subject: Re: Can a sound card be used as an A/D? Date: Wed, 29 Oct 1997 12:27:37 -0800 Dewayne (n0ssy) and Linda (n0uqf) Hill wrote: > Hi to all, > With no knowledge as to the inter-workings of the Sound Blaster sound > card or the software to support it and my general knowledge of > electornics is seem to me that all a sound card is is an A/D converter > (it has an output - spearker out and an input - Mic in.) > > I am want to know if anyone has tried to connect the output from a > senseing coil straight into a sound card. Can this type of connection > be made to work? > > Any info would be helpful. > > Regards, Dewayne Hill Hi Dewayne, Yup, I tried it just for laughs using my SoundBlaster16 card in my work computer. The problem is that the lowest sampling rate is 11025 Hz. Windows has a voice recorder that works with the sound card but it's lowest sampling rate is ~8kHz, you're really going to use up the big-a-bytes at that speed. The other problem is the frequency response of the sound card at very low frequencies. I think everyone would agree that if you're going to do it, do it with one of Larry's ADC cards. Jim cristiano@........... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "David A. Nelson" Subject: Re: another addition Date: Thu, 30 Oct 1997 09:42:16 +1200 Well I guess someone was going to haul me over the coals.... thanks Greg.... I didn't know Florida was so named about the only thing I was really sure of is that New York is known worldwide as the "Big Apple" why ??? I have never heard. well that's the good thing about this group, we shape not only info about our hobby.. seismology... but also a bit about the world around us chow Dave >Oops! That may not keep the peace among Californians, since Florida is the "Sunshine State"! :-) >California claims to be the "Golden State". We need to keep this list >technically accurate after all! - Greg 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: R: Can a sound card be used as an A/D? Date: Thu, 30 Oct 1997 01:24:42 +0100 Hi to all, i'm busing to build my sismo station in italy with other friends Roberto and Giovanni. I have installed the horizontal long period sensor, built by Elkron Srl (Bologna, Italy). It's a good instrument, from many years used by Roberto Pozzo for his meteo-sesismic station on Nizza Monferrato. Now, the most important problem is the A/D converter card for the computerized analysis. Unfortunately, the Larry's card is not compatible with the analog imput mark, like I have had way already of audit with my friend Giovanni Rotta. In italy, I don't succeed to find no that cause th= e card or I have found one of it, but too high price. Could I use a Sound Blaster? His tension of analog input is < 1 volt. The output of the sensor is 0/ 5 volts, but before the entry into Sound Blaster is possible apply a reduction gear of strain The Sound Blaster has a response of frequency < 20 Khz. It could be good for our custom. This card it I want to use to run SDR. It's possible all this? Thank you for the responses ---------- > Da: jim cristiano > A: PSN-L Mailing List > Oggetto: Re: Can a sound card be used as an A/D? > Data: mercoled=EC 29 ottobre 1997 21.27 > = > Dewayne (n0ssy) and Linda (n0uqf) Hill wrote: > > Hi to all, > > With no knowledge as to the inter-workings of the Sound Blaster sound= > > card or the software to support it and my general knowledge of > > electornics is seem to me that all a sound card is is an A/D converte= r > > (it has an output - spearker out and an input - Mic in.) > > = > > I am want to know if anyone has tried to connect the output from a > > senseing coil straight into a sound card. Can this type of connection= > > be made to work? > > = > > Any info would be helpful. > > = > > Regards, Dewayne Hill > = > Hi Dewayne, > Yup, I tried it just for laughs using my SoundBlaster16 card in my > work > computer. The problem is that the lowest sampling rate is 11025 Hz. = > Windows has a voice recorder that works with the sound card but it's > lowest sampling rate is ~8kHz, you're really going to use up the = > big-a-bytes at that speed. The other problem is the frequency respons= e > of the sound card at very low frequencies. > = > I think everyone would agree that if you're going to do it, do it wit= h > one of Larry's ADC cards. = > = > Jim cristiano@........... > = > _____________________________________________________________________ > = > 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: Pete Subject: AD Converter Date: Wed, 29 Oct 1997 23:06:54 -0800 PSN, I have an 8 channel 10 bit A to D converter that works on a parallel port. It has a chart recorder software program with it. The program does not really work as a seismic data recorder because of the size of the files it produces. I am thinking of writing a program that will work just like SDR. Because it is 10 bits, would it be a waste of time? The cost of producing a AD converter of this type is extremely cheap! I can sample up to 4000 times a second if I want to. Perhaps I could make the files compatible with SDR? I plan to buy an AD converter from Larry but it will be a few months because I'm on a tight budget. Thanks, Pete Fleming _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: SG output Date: Thu, 30 Oct 1997 00:49:59 -0700 Hi Barry, I'm not sure about summing the two together. What type of signal would that produce? Give it a try.... -Larry At 08:27 PM 10/25/97 -0700, you wrote: >Larry > I have been playing around with my SG sensor. The recent Trinidad >event only showed low frequency output. You have mentioned about taking >two outputs,one before and one after the integrator and recording them. >I think I'm going to try putting a summing amp after and adding the two. >Because the integrator is inverting I will change the sign of the signal >so the two signals have the same sign. What do you think? > 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: GeE777@....... Subject: Re: Can a sound card be used as an A/D? Date: Thu, 30 Oct 1997 05:14:32 -0500 (EST) Hi Dwayne, I thought of that but found the sample rate to be excessively high and wasting memory for the frequencies we are interested in. At the present time I am interested in only local seismic events so I use a seismic exploration type geophone connected to a MultiPurpose Lab Interface by Vernier Software, of Portland, Oregon, USA I sample the data every 8 milliseconds and run it through a home brew amplifier and anti-aliasing filter. In a message dated 97-10-29 14:13:02 EST, n0ssy@................ writes: << I am want to know if anyone has tried to connect the output from a senseing coil straight into a sound card. Can this type of connection be made to work? Any info would be helpful. >> _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: Can a sound card be used as an A/D? Date: Thu, 30 Oct 1997 02:32:57 -0700 I looked into sound cards when I first got into seismic recording a few years ago. The problem is the low end frequency response of the card. All of the specs I could find on the boxes had a ~10 Hz low end. We are dealing with much lower frequency range. Since sound cards only have too deal with the audio range, there is no need to design a sound card that can do DC, or, have a very low end. If someone knows of a "standard" sound card that can go lower then the normal audio range please let me know. As far as the sample rate, that can be handled in software. -Larry Cochrane Redwood City, PSN At 12:06 PM 10/29/97 -0700, Dewayne Hill wrote: >Hi to all, > >I have been interested in setting up a seismeter in my house for >sometime. I have aquired some large magnets (from and IBM 3380 disk >drive.) Now I have to get some type of A/D card and software for my PC. > >With no knowledge as to the inter-workings of the Sound Blaster sound >card or the software to support it and my general knowledge of >electornics is seem to me that all a sound card is is an A/D converter >(it has an output - spearker out and an input - Mic in.) > >I am want to know if anyone has tried to connect the output from a >senseing coil straight into a sound card. Can this type of connection >be made to work? > >Any info would be helpful. > >Regards, Dewayne Hill _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Karl Cunningham Subject: Re: Can a sound card be used as an A/D? Date: Thu, 30 Oct 1997 08:11:56 -0800 Although I haven't looked into it, the low-frequency response of a sound card's input is probably governed by a series capacitor and shunt resistor somewhere in the signal path to the A/D -- most likely right at the input to the card. There could be more than one stage of this too. One could increase the size of the cap(s) to reduce the low end cutoff, but the low-frequency stability (temperature drift) of the A/D and/or amplifiers on the card could be a problem. Karl Cunningham La Mesa, CA. PSN station #40 karlc@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jack Ivey Subject: RE: Can a sound card be used as an A/D? Date: Thu, 30 Oct 1997 11:53:39 -0500 Sound cards will probably all be AC coupled so that very low frequencies will be attenuated. One way to get around this problem would be to "chop" the signal with a high frequency (1 kHz?) carrier, so the signal the sound card sees is a 1kHz square wave whose peak-to-peak amplitude changes with the input voltage. This could be done with an oscillator, a couple of op amps and an analog switch. It will require demodulation in the software, which would be fairly simple. Demodulation could also get rid of the excess data. The scheme sounds odd, but it was used for DC amplifiers in the vacuum tube era and more recently for high precision amps. > >I looked into sound cards when I first got into seismic recording a few >years ago. The problem is the low end frequency response of the card. All >of the specs I could find on the boxes had a ~10 Hz low end. We are dealing >with much lower frequency range. Since sound cards only have too deal with >the audio range, there is no need to design a sound card that can do DC, >or, have a very low end. If someone knows of a "standard" sound card that >can go lower then the normal audio range please let me know. > >As far as the sample rate, that can be handled in software. > >-Larry Cochrane >Redwood City, PSN > > >At 12:06 PM 10/29/97 -0700, Dewayne Hill wrote: >>Hi to all, >> >>I have been interested in setting up a seismeter in my house for >>sometime. I have aquired some large magnets (from and IBM 3380 disk >>drive.) Now I have to get some type of A/D card and software for my PC. >> >>With no knowledge as to the inter-workings of the Sound Blaster sound >>card or the software to support it and my general knowledge of >>electornics is seem to me that all a sound card is is an A/D converter >>(it has an output - spearker out and an input - Mic in.) >> >>I am want to know if anyone has tried to connect the output from a >>senseing coil straight into a sound card. Can this type of connection >>be made to work? >> >>Any info would be helpful. >> >>Regards, Dewayne Hill >>> _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Norman Davis WB6SHI Subject: Re: Can a sound card be used as an A/D? Date: Thu, 30 Oct 1997 12:11:46 At 02:32 AM 10/30/97 -0700, you wrote: >I looked into sound cards when I first got into seismic recording a few >years ago. The problem is the low end frequency response of the card. All >of the specs I could find on the boxes had a ~10 Hz low end. We are dealing >with much lower frequency range. Since sound cards only have too deal with >the audio range, there is no need to design a sound card that can do DC, >or, have a very low end. If someone knows of a "standard" sound card that >can go lower then the normal audio range please let me know. > >As far as the sample rate, that can be handled in software. > >-Larry Cochrane >Redwood City, PSN Why couldn't you feed the output of the dc amp to a vco and then feed the vco output into the soundcard and fftdsp. Norman Davis WB6SHI Email normd@............. Shingle Springs, Ca, USA it ain't local... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "David A. Nelson" Subject: New Addition Date: Fri, 31 Oct 1997 12:08:28 +1200 hi ya 'll, please welcome our latest newcomer to the group map and database. Meredith Lamb, who hails from Denver, Colorado. Chow 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: frankcnd@.......... (Frank Condon) Subject: Re: Can a sound card be used as an A/D? Date: Thu, 30 Oct 1997 18:36:06 -0800 (PST) Hi Larry: Yes, I know of a sound card that goes down to DC! It is the Multi-Sound Monterey from Turtle Beach. The sampling rate is the only snag as far as I can determine to be using it for seismic detection. The only way I can get it to work properly is if I use Spectra-Plus software for data acquisition. Actually, I used this setup to watch the 0-3 Hz region for a long time. If you try to capture the real-time data it will cost you plenty of hard drive space. I successfully used it in the data-logger mode. I sampled every 20 seconds and charted the amplitude to look for variations at a certain frequency. The air-core coil that I used as a sensor was very sensitive to 60 Hz. So, I installed a low-pass filter onto the front-end of the Monterey. Frank Condon mail to: frankcnd@.......... >I looked into sound cards when I first got into seismic recording a few >years ago. The problem is the low end frequency response of the card. All >of the specs I could find on the boxes had a ~10 Hz low end. We are dealing >with much lower frequency range. Since sound cards only have too deal with >the audio range, there is no need to design a sound card that can do DC, >or, have a very low end. If someone knows of a "standard" sound card that >can go lower then the normal audio range please let me know. > >As far as the sample rate, that can be handled in software. > >-Larry Cochrane >Redwood City, PSN > > >At 12:06 PM 10/29/97 -0700, Dewayne Hill wrote: >>Hi to all, >> >>I have been interested in setting up a seismeter in my house for >>sometime. I have aquired some large magnets (from and IBM 3380 disk >>drive.) Now I have to get some type of A/D card and software for my PC. >> >>With no knowledge as to the inter-workings of the Sound Blaster sound >>card or the software to support it and my general knowledge of >>electornics is seem to me that all a sound card is is an A/D converter >>(it has an output - spearker out and an input - Mic in.) >> >>I am want to know if anyone has tried to connect the output from a >>senseing coil straight into a sound card. Can this type of connection >>be made to work? >> >>Any info would be helpful. >> >>Regards, Dewayne Hill > > >_____________________________________________________________________ > >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: SG output Date: Thu, 30 Oct 1997 08:43:37 -0800 Larry I was having problems with the opamp-coil feedback circuit so I am using the coil with a variable shunt resistor for damping. Like the Lehman I am taking the output from this coil as the high frequency input to to summing amp. For the low frequency I'm using the output from the integrator. I am fiddling with the input resistors to the summing amp so as to get the proper proportion of high and low frequency components. I guess what I really have is Lehman circuitry with an integrator from the pendulum deflection to increase the low frequency end(both velocity). Hopefully I can upload some local and teleseismic events to see how it performs. Barry Larry Cochrane wrote: > > Hi Barry, > > I'm not sure about summing the two together. What type of signal would that > produce? Give it a try.... > > -Larry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "James M Hannon" Subject: Re: Can a sound card be used as an A/D? Date: Fri, 31 Oct 1997 06:56:32 -0600 I suspect that there are more than one type of sound card that goes to DC. I set up a RealAudio WEB server here at work and they warn you that for best sound quailty you have to make shure there is no DC offset in your audio input signal to the sound card. This implies a DC response for the sound card. To deal with the large data files you can do what is referred to in the DSP world as decimation. In other words throw away all the samples in between the ones you want to keep. To do this with soundcard data you must either provide an external antialias filter with the apporpriate response or do the decimation with a decimation filter which reduces the bandwidth at the same time it removes samples. If you write your own driver for the sound card this can all be done in software as the data is stored to disk. Jim Hannon frankcnd@.......... on 10/30/97 08:36:06 PM Please respond to psn-l@............. To: psn-l@............. cc: (bcc: James M Hannon/CedarRapids/Collins/Rockwell) Subject: Re: Can a sound card be used as an A/D? Hi Larry: Yes, I know of a sound card that goes down to DC! It is the Multi-Sound Monterey from Turtle Beach. The sampling rate is the only snag as far as I can determine to be using it for seismic detection. The only way I can get it to work properly is if I use Spectra-Plus software for data acquisition. Actually, I used this setup to watch the 0-3 Hz region for a long time. If you try to capture the real-time data it will cost you plenty of hard drive space. I successfully used it in the data-logger mode. I sampled every 20 seconds and charted the amplitude to look for variations at a certain frequency. The air-core coil that I used as a sensor was very sensitive to 60 Hz. So, I installed a low-pass filter onto the front-end of the Monterey. Frank Condon mail to: frankcnd@.......... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: A/D converters Date: Fri, 31 Oct 1997 09:58:00 -0500 Hi gang, A variety of A/D converters has been discussed lately. An important attribute of A/D converters is dynamic range and the recent discussion ha= s not made much mention of this. Even here in New Jersey where strong shaking is almost never seen (unle= ss I go out in the winter with a thin coat), 16 bits of resolution is not excessive. On July 16, 1996, Larry gave an admirable discussion of dynamic range a= nd other considerations. This is well worth looking up in the archives. Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Robert L. Thomasson" <102073.3346@..............> Subject: A/D converters Date: Fri, 31 Oct 1997 11:07:33 -0500 Can anyone recommend any good books on digital signal processing? I've found a lot of titles listed on amazon.com, but at $75++ per book, I'm ki= nd of chicken to buy one without a recommendation. Thanks, Bob _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "James M Hannon" Subject: Re: A/D converters Date: Fri, 31 Oct 1997 10:43:58 -0600 >Can anyone recommend any good books on digital signal processing? I've >found a lot of titles listed on amazon.com, but at $75++ per book, I'm kind >of chicken to buy one without a recommendation. >Thanks, Bob It depends a lot on what you want to do and where you are coming from. Here are two books that are reccomended around here at work. Theory and Application of Digital Signal Processing by Rabiner and Gold Prentice-Hall Discrete-Time Signal Processing by Oppenheim & Schafer ISBN 0-13-216292-X Jim Hannon _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Robert L. Thomasson" <102073.3346@..............> Subject: Re: A/D converters Date: Fri, 31 Oct 1997 14:29:12 -0500 Jim, Thanks for the book references. <= > This is only peripherally related to psn business, so I'll keep it short and promise not to do it again. I'm a mechanical engineer (read electronically and softwarily challenged), and I work with industrial vibration monitoring equipment that takes an accelerometer signal, integrates it to velocity and/or displacement, then performs FFT's and th= e results can be stored and displayed in various graphical formats. I'd li= ke to understand the nuts and bolts of how these hardware/software systems work so I can modify them to suit my own purposes. If that's not practical, I just want to understand how they work. Regards, Bob Thomasson _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Roger Baker Subject: Re: A/D converters Date: Fri, 31 Oct 1997 15:10:58 -0600 Friends, On the topic of A/D converters, the latest Radio Shack catalogue, p 173, has a nifty little two channel 12 bit converter called DATAQ that samples DC up to 250 samples per second and plugs into the serial port (you need another free serial port for your mouse). The company worked out the bugs dealing with industrial customers and has now branched out to the consumer market. They offer free phone support. It costs $100, and various other models are available for specialized applications. It is quite versatile and comes with easy to use software that lets you do setup and then record data from almost any analogue circuit up to 30 volts or so. In general it will turn your Windows 95 PC into a chart recorder for about any reasonable voltage level and sampling rate and specified file size you want. I got one and I love it and have not encountered any important deficiencies. It gets its own power from the port. I use it with an op amp buffer output from the analog circuit and about 35 feet of speaker wire to the device, which is about the size of a matchbox with screw terminals, and a five foot or so serial cable that comes with it leads to the computer port. On the other hand, you're probably better off with one of Larry's boards if your interests are strictly seismographic. --Yours, Roger Baker _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert Avakian Subject: Re: A/D converters Date: Fri, 31 Oct 1997 23:38:02 -0800 The cost of technical books is an all prevasive problem. Let me offer a couple of sites for everyone's consideration: abebook.com and interloc.com. I have dealt with dealers on both systems with complete satisfaction. ABE has a feature that lets you put in your want list on their computer and you recieve an E-mail if a matching item is posted on their system. Very slick. Bob Avakian Robert L. Thomasson wrote: > > Can anyone recommend any good books on digital signal processing? I've > found a lot of titles listed on amazon.com, but at $75++ per book, I'm kind > of chicken to buy one without a recommendation. > > Thanks, Bob > > _____________________________________________________________________ > > 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: Larry Cochrane Subject: Re: A/D converters - Dynamic Range Date: Sat, 01 Nov 1997 03:04:16 -0700 At 09:58 AM 10/31/97 -0500, Robert L Barns wrote: >Hi gang, >> On July 16, 1996, Larry gave an admirable discussion of dynamic range and >other considerations. This is well worth looking up in the archives. >Bob Barns I have this on the web at http://psn.quake.net/dynamic.txt. I'm not sure about the admirable part . -Larry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: prewar Subject: Concrete foundations and DECOUPLING Date: Sat, 01 Nov 1997 20:01:41 +0000 Hello, I see from list of PSN sites that many have large concrete blocks upon which the seismos are fixed. I too have a heavy concrete block, 2ft long x 1.5 ft wide x 2ft DEEP. The block is FLUSH with the ground surface, but ONLY the bottom 6 inches of the block is in contact with the ground. (It is pinned into the ground with 3/4 dia steel driven into earth at bottom last 6 inches). My reason for doing this was to decouple the block from any earth movements at ground level.......footsteps, SMALL roots of hedges and trees etc. I am now rather concerned that being situated on clay, then the inertia of a 1/5th ton block will not allow it to move as the earth beneath does. Should I 'fill in' the top 18 inches and ensure that ALL the block is in direct contact with earth or not ?? Will the block be decoupled and act as a cherry on top of jelly if I don't? If anyone with concrete blocks has considered above I would like to know of their experiences, and what they did. Thanks. Regards, Albert Noble (England). _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Dennis Eckert" Subject: Seismic radio monitoring Date: Sat, 1 Nov 1997 13:36:26 -0800 I'm new to the list. Is anyone selling or offering as shareware a program that allows you to connect an audio cable from a radio receiver (like a scanner) to a SoundBlaster-compatible card? This would allow you to monitor the various radio transmitters broadcasting seismic signals. I've seen the site where you can buy a board to do this, but wondered if this other approach has been done. I enjoy monitor data traffic on radios, and there are a number of freeware programs that now work this way (take the audio from the radio receiver and input into the mike or line input of the sound card). Dennis Eckert KB7ST (Amateur Radio Operator) Flies Standard Cirrus sailplane (SV) In Western & Eastern Washington _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "David A. Nelson" Subject: Willmore seismometer Date: Sun, 02 Nov 1997 17:17:46 +1200 hi all, I have borrowed a Willmore MKI or II vertical seismometer for a couple of months to try out. do any of you have practical experience in using one of these beasts. a few comments about it..... it is encased in a steel cylinder ~5" dia. and 10" high. weighs ~10lb (very solid) the top of the seismometer is adorned with a chromed steel carry handle, a levelling bubble, a single fine threaded screw which is screwed right down to clamp the internals during transportation and a red coloured "needle" in a 1" high perspex dome to indicate operation of the seismometer. It has a period that can be adjusted (by a setting inside) from 1 sec to 3 sec OK.... problem.... how/how much ... do I damped this beast at the moment I have a 3k resistor across the output of the coil and this does dampen it to some extent.... one comment on a MKIII unit said 7k resistive load I started at 10k and decreased value watching the results at present with ~3k if the seism. is tapped it will give ~6 cycles before returning to a flat line. The cycles decrease evenly so the overall waveform is triangular shaped (starting large p-p, dying off rapidly know what I mean??) Not having a lot of experience with longer period units it the above 6 odd cycles too much. I dont want it doing its own thing instead of faithfully recording ground movement The voltage output from this unit is huge compared to my geophones, so much so that event with the gain set at minimum on one of Larrys preamp brds. it was still overloading and I had to do component changes to substantially reduce the pre amps overall gain. for your thoughts Dave PS hope you all like the new Hi Res Californian PSN map I was trying to wait for someone to comment but couldn't resist any longer. oh dear I have no will power 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: Willmore seismometer Date: Sat, 1 Nov 1997 23:01:59 -0800 (PST) At 05:17 PM 11/2/97 +1200, you wrote: >hi all, > I have borrowed a Willmore MKI or II vertical seismometer for a >couple of months to try out. do any of you have practical experience in >using one of these beasts. Hi Dave, I have somewhere in my accumulation of Seismo info something that stated that critical damping should bring the impulse signal down to 1 percent in three cycles. If you loaded it with lower resistance to get this kind of damping it would also reduce the output to a more usable value. I am using 500 ohms to damp my seismometer. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Al Allworth Subject: Re: Willmore seismometer Date: Sat, 1 Nov 1997 23:04:01 -0800 (PST) I just thought of another question. What is the internal resistance of the seismometer? _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "David A. Nelson" Subject: Re: Willmore seismometer Date: Sun, 02 Nov 1997 20:28:03 +1200 Hi Al, just went out and measured the coil resistance 500ohms at one stage I went as low as 560 ohms with a load resistor other willmores I have read about have coil resistances up to 8000 ohms Dave At 11:01 PM 11/1/97 -0800, you wrote: Hi Dave, >I have somewhere in my accumulation of Seismo info something that stated >that critical damping should bring the impulse signal down to 1 percent in >three cycles. If you loaded it with lower resistance to get this kind of >damping it would also reduce the output to a more usable value. I am using >500 ohms to damp my seismometer. Al 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: GeE777@....... Subject: Re: Willmore seismometer Date: Sun, 2 Nov 1997 06:16:01 -0500 (EST) Hello all, I know that we in the seismic exploeation business try to dampen our geophones so they will return to zero as soon as possible fron an impulse. That is, not ringing (cycling) [not enough damping] or slowly returning to zero [too much damping] In a message dated 97-11-02 02:04:04 EST, aallworth@........ writes: << I have somewhere in my accumulation of Seismo info something that stated that critical damping should bring the impulse signal down to 1 percent in three cycles. >> _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "David A. Nelson" Subject: Calif/Nevada BDR Date: Mon, 03 Nov 1997 00:12:56 +1200 well all you californian guys a Mw5.7 must have given you gear a good workout 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: curtis Subject: re: Seismic radio monitoring Date: Sun, 02 Nov 1997 06:17:00 -0800 gm dennis and greetings list, take a look at http://www.relisoft.com/ . about half way down the page there are the keywords "Whistle a melody" which is the location of a "real time frequency analyzer", http://www.relisoft.com/freq.html , i use on my dec alphas' (it also works on the x86 platform). i use the 'line in' on a soundblaster (rather than the mic. input) and observe seismic transmitter activity (smile - at a minimum) while i am working on my other projects. i am also new to this list and have spent most of my (smile) 'entry time' reading documentation, with anticipation of building my own station. in due process, i will properly introduce myself to the list, but in the meantime, here's a little information. i have successfully optimized larry's 'WinQuake beta release' to work on my dec alpha xlt300/nt4.0/sp3/fx!32v1.2. fx!32 is digital's new x86 emulator. (fwiw) i have aprox. 18 years unix and 1 1/2 years nt back- ground (smile = nt newbie). i am located at 38.45n, 122.37w, on the side of an old volcano, at aprox. elevation 2600'. this area, on the charts, is known as "The Geysers" and the closest (now capped) geyser is aprox. a 15 min. walk through the woods from my front door. (smile) i have 'tinkered' with amateur seismology, for a long time, and when i finally get into 'building mode' (soon) will probably have a lot of questions so (chuckle) list beware. best2u, curtis - n6ect -- curtis - ufkartfm@........... - site administrator for Nobody I want Nobody to control my Life! How about You? http://www.netvideo.com/nobody _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: Calif/Nevada BDR Date: Sat, 01 Nov 1997 20:46:21 -0800 Dave I've picked up three so far. The main event on low gain . Will upload as soon as I get times etc. Barry David A. Nelson wrote: > > well all you californian guys a Mw5.7 must have given you gear a good > workout > > Dave _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Mike Stickney Subject: Re: Concrete foundations and DECOUPLING Date: Sun, 2 Nov 97 09:54:16 MST Albert: Seismic piers installed in the basements of buildings are typically constructed in the manner you describe. The concrete pier is poured on the material below building slab grade (hopefully bedrock). It projects up through the building floor with a surrounding 1-2 inch air gap such that the building floor never comes into direct contact with the sides of the pier. I don't know how much actual decoupling from activities in the building this method provides, but in my experience, it has not introduced any spurious effects. At the frequencies of interest to you, I doubt your seismic piers will give you problems. -Mike Stickney Earthquake Studies Office Montana Bureau of Mines and Geology Butte Montana http://mbmgsun.mtech.edu/ ====================================== At 08:01 PM 11/1/97 +0000, you wrote: >Hello, > I see from list of PSN sites that many have large concrete >blocks upon which the seismos are fixed. I too have a heavy >concrete block, 2ft long x 1.5 ft wide x 2ft DEEP. The block is >FLUSH with the ground surface, but ONLY the bottom 6 inches >of the block is in contact with the ground. (It is pinned into the >ground with 3/4 dia steel driven into earth at bottom last 6 inches). > > My reason for doing this was to decouple the block from any earth >movements at ground level.......footsteps, SMALL roots of hedges >and trees etc. > >I am now rather concerned that being situated on clay, then the >inertia of a 1/5th ton block will not allow it to move as the earth >beneath does. Should I 'fill in' the top 18 inches and ensure that >ALL the block is in direct contact with earth or not ?? Will the >block be decoupled and act as a cherry on top of jelly if I don't? > >If anyone with concrete blocks has considered above I would >like to know of their experiences, and what they did. Thanks. > > Regards, > > Albert Noble (England). > > > >_____________________________________________________________________ > >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: Fish Lake Valley M5.3 aftershocks Date: Sun, 02 Nov 1997 10:33:49 -0700 A pretty good aftershock sequence is following the Fish Lake Valley, Nevada, M5.3 earthquake. I wish I could get away to go down there and feel 'em. It's only a 3 hr drive from my office. Rats! -- ---/---- 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: John Taber Subject: re: Willmore seismometer Date: Mon, 3 Nov 1997 10:22:32 +1300 (NZDT) t 05:17 PM 11/2/97 +1200, you wrote: >hi all, > I have borrowed a Willmore MKI or II vertical seismometer for a >couple of months to try out. do any of you have practical experience in >using one of these beasts. Hi Dave, I just happen to have an old Willmore manual which I can copy and send to you if you are interested. I use the Willmore in a geophysics class lab where the students learn some of the basics about seismometers. Our Willmore has a 380 ohm coil, and critical damping (when there is no oscillation) is somewhere around 220 ohms. Typically the damping is set to 0.6-0.7 of critical damping. This is the point where the amplitude decreases by a factor of about 20 between successive half cycles, which seems to be a greater amount of damping than dropping to 1% after 3 cycles, as suggested by Al Allworth. John Taber School of Earth Sciences Victoria University of Wellington PS I get the PSN list as a daily digest so you should also email me directly if you want a quick response. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Robert L. Thomasson" <102073.3346@..............> Subject: Fish Lake Valley M5.3 aftershocks Date: Sun, 2 Nov 1997 16:42:27 -0500 Charles, <> Hmmm..I wonder if one could take on old 15" JBL studio monitor loudspeake= r and bolt it to the bottom of a chair and somehow couple the voice coil to= the seat and connect it to a computer audio output. You'd obviously als= o have to uncouple the chair seat from the floor. No scientific value that I can see, but it might be a great classroom demonstration to help get kids interested in seismology. The basic concept might have some merit, but if it does, I'm sure someone's already= done it. I'm right across the valley from you, out in the sage behind the NDF Fire= station on Mt Rose Hwy. I won't have my station up and running 'til at least spring, but it might be interesting to compare responses. = Regards, Bob _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: watson@................ (Charles Watson) Subject: Re: Fish Lake Valley M5.3 aftershocks Date: Sun, 02 Nov 1997 15:22:40 -0700 Called Diane de Polo up at the UNR seismo lab. They had been fine tuning the new Earthwarm system this past week and Diane said she was watching the monitor rip off event after event then a big one then another and another... She has a trillion M1's! -- ---/---- Charles _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Roseberry Subject: Geo-Monitor Date: Sun, 02 Nov 1997 18:12:23 -0600 Group: I am interested in acquiring all the past issues of Geo-Monitor, the earthquake prediction newsletter. Is there anyone out there who may have all or most of the past issues of this newsletter and would be interested in selling or giving :-) them to me? The former publisher offers most back issues -- but for a pretty hefty price -- so before I go that route I thought it might be prudent to inquire of the members of this list. I haven't seen many threads of discussion on the topic of earthquake prediction in the last year or so; there was considerable interest on this list about two years ago when I first tuned in. Anyone out there still winding coils and such? Or is it now considered a dead end? Michael J. Roseberry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: watson@................ (Charles Watson) Subject: [Fwd: Press Release (fwd)] Date: Sun, 02 Nov 1997 17:20:12 -0700 FYI -- ---/---- 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 ####################################################################### John G. Anderson Phone: (702) 784-4265 Seismological Laboratory / 174 FAX: (702) 784-1833 or 784-1766 University of Nevada jga@.............. Reno, Nevada 89557 ####################################################################### ---------- Forwarded message ---------- Date: Sun, 2 Nov 1997 15:22:23 -0800 (PST) From: John Anderson To: nveqfax@.................... Cc: Mackay all Subject: Press Release 2 November 1997 2:30 PM PDT Press Release Seismological Laboratory University of Nevada, Reno A magnitude 5.4 earthquake occurred at about 1 AM on November 2, 1997, in northern Fish Lake Valley, Nevada, about 60 miles west-southwest of Tonopah, Nevada. The preliminary location for the event determined by the University of Nevada Reno, Seismological Laboratory is; 37 Degrees 50.78 Minutes NORTH latitude, 118 Degrees, 12.86 Minutes WEST longitude. The preliminary depth estimate is 6 km (4 mi). This places the earthquake near the northern end of the Fish Lake Valley Fault Zone. The origin time of the earthquake is: November 2, 1997, 12:51 AM, Pacific Standard Time. The earthquake was preceded by a relatively strong foreshock (M=4.2) at 12:34 AM. The area had also become more active with very small earthquakes over the past week or so. Dirk Andrews, the Fire Chief for Fish Lake Valley, reported to the Seismological Laboratory that for the past week, rumbles were heard in the White Mountains - possibly an earthquake sound phenomenon caused by tiny shocks moving the surface of the ground like a loudspeaker. There is a strong aftershock sequence for todays earthquake. AT 1:00 PM, we were still recording over 100 small aftershocks per hour on our nearest station. The two largest aftershocks so far were at 7:02 AM (M=4.6) and 8:22 AM (M=4.2). Todays earthquake was in an area where earthquakes are to be expected. The Fish Lake Valley Fault Zone, and several other faults near the location of todays earthquake, are quite active from the geological viewpoint. The Eureka Valley earthquake, May 17, 1993, M=6.1, was about 50 miles southeast of todays earthquake. Todays earthquake is the largest event that has occurred in Nevada since the Double Spring Flat earthquake on September 12, 1994. That earthquake, magnitude 6.0, located 12 miles south-southeast of Gardnerville, was widely felt throughout the Reno-Carson City area. The Seismological Laboratory has received felt reports for todays earthquake from locations as far as Tonopah and Fallon, Nevada, and Fresno, California. The Seismological Laboratory has not received any reports of damage at this time. The data reported here is preliminary. For more information, contact the Seismological Laboratory at 702-784-4975, or http://www.seismo.unr.edu. The free pamphlet: "Earthquakes in Nevada and How to Survive Them" is available on request. ####################################################################### John G. Anderson Phone: (702) 784-4265 Seismological Laboratory / 174 FAX: (702) 784-1833 or 784-1766 University of Nevada jga@.............. Reno, Nevada 89557 ####################################################################### From: Stephen Caruso Subject: Earthwarm Project? Date: Sun, 2 Nov 1997 21:59:30 -0500 (EST) Sounds very interesting this earthwarm project. Is there a web site? 100's of M1's? STEPHEN CARUSO CET KB8UGH "Coincidence is a shortsighted mental delusion" _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Norman Davis WB6SHI Subject: re: Seismic radio monitoring Date: Sun, 02 Nov 1997 09:35:34 http://www.relisoft.com/freq.html , i >use on my dec alphas' (it also works on the x86 platform). As I am alway looking for something better I checked it out. A nice simple program but no record capability. A better program is fftdsp at http://www.webcom.com/~af9y/ the only problem is the program only runs one min then stops unless you register it. Not enough time to evaluate it. I know of a number of serious fold uning it and I have just registered it. It is a neat program and worth the 32 bucks. Norman Davis WB6SHI Email normd@............. Shingle Springs, Ca, USA it ain't local... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jim Cristiano Subject: Re: shake transducer Date: Sun, 02 Nov 1997 20:29:41 -0800 Robert L. Thomasson wrote: > > Charles, > > <> > > Hmmm..I wonder if one could take on old 15" JBL studio monitor loudspeaker > and bolt it to the bottom of a chair and somehow couple the voice coil to > the seat and connect it to a computer audio output. You'd obviously also > have to uncouple the chair seat from the floor. Since you mentioned it, Aura Systems makes floor shaker transducers for sound systems. It's ~ 5" dia. and bolts to the car body under the seats or to the floor and creates the subaudible "thump" you feel when the stereo is cranked up. Instead of the fixed magnet moving the coil and cone, as in a conventional dynamic speaker, the coil is fixed and the magnet (mass) moves. Bolt one of these to the table top and feed it the right frequency (or seismic signal) and stuff is going to walk right off the table. ( just in case someone wanted to bolt one to the bottom of a chair) Jim cristiano@........... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: New Ca map Date: Sun, 02 Nov 1997 20:31:28 -0700 Looks great Dave! Thanks.... -Larry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Walt Williams" Subject: Re: shake transducer Date: Sun, 2 Nov 1997 21:51:36 +0000 Hello, 2 pennies worth Four old mainframe hard disk transport voice coil assemblies mounted in the vertical axis could be used? Even has the attendant power amps and they are digital drive ultimately? If you are like me and have some old stuff laying about. Walt Williams, 97.11.02 dfheli@.............. http://www.pacificnet.net/~dfheli Woodland Hills, California USA ========================================== driver ------- Forwarded Message Follows ------- Date: Sun, 02 Nov 1997 20:29:41 -0800 From: Jim Cristiano Reply-to: PSN-L Mailing List Organization: weitech To: PSN-L Mailing List Subject: Re: shake transducer Robert L. Thomasson wrote: > > Charles, > > <> > > Hmmm..I wonder if one could take on old 15" JBL studio monitor loudspeaker > and bolt it to the bottom of a chair and somehow couple the voice coil to > the seat and connect it to a computer audio output. You'd obviously also > have to uncouple the chair seat from the floor. Since you mentioned it, Aura Systems makes floor shaker transducers for sound systems. It's ~ 5" dia. and bolts to the car body under the seats or to the floor and creates the subaudible "thump" you feel when the stereo is cranked up. Instead of the fixed magnet moving the coil and cone, as in a conventional dynamic speaker, the coil is fixed and the magnet (mass) moves. Bolt one of these to the table top and feed it the right frequency (or seismic signal) and stuff is going to walk right off the table. ( just in case someone wanted to bolt one to the bottom of a chair) Jim cristiano@........... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "David A. Nelson" Subject: Major Solar Flare Alert Date: Wed, 05 Nov 1997 00:25:34 +1200 hi all, Early in the utc day on the 4th Nov. a large X-class proton flare eminated from Region 8100. It is the 1st x-class flare for the new solar cycle and the first for a number of years. It was preceeded by a M2 and a M4 flare. This region has been growing very quickly in complexity over the last 3 days and on the 3rd Nov. I counted 30 spots in the group. The huge outpouring of x-rays from this event caused a strong PCA (Polar Cap Absorption ) event that started between 0900 and 1030 UTC 4 Nov. My reception of 10MHz WWV went from very clear and stable to extremely distorted over that period. The protons from this event travel somewhat slower (~600 to 1000 km/sec) and are expected to arrive within the next 24 to 40 hours. Their arrival will herald the start of strong auroral storming and any of you with working magentometers should be able to record the impact with the Earth's geomagnetic field as it buckles under the stress. Keep your eyes on the sky nthrn hemisp. to the nth and the sthrn hemisp. to the sth (of course) pray for clear skies you guys in alaska, canada, new york state should get a great view. 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: watson@................ (Charles Watson) Subject: Re: Major Solar Flare Alert; web site news Date: Tue, 04 Nov 1997 07:10:05 -0700 Read about the recent solar flare here: http://dxlc.com/solar/index.html Should be a wooper! -- ---/---- 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: "David A. Nelson" Subject: Re: Major Solar Flare Alert; web site news Date: Wed, 05 Nov 1997 08:12:09 +1200 The timing of the flare at this site seems to be 40 minutes late the "horses mouth " report stated 0558 UTC at this site you will find images of the sun in different wavelengths eg. x-ray, helium, iron, etc. http://umbra.gsfc.nasa.gov/images/latest.html the very bright region in the lower right corner of the sun is Region 8100 and this is where the activity is coming from Dave At 07:10 AM 11/4/97 -0700, you wrote: >Read about the recent solar flare here: >http://dxlc.com/solar/index.html> >Should be a wooper! >Charles P. Watson, Consulting Geologist 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: MLamb12830@....... Subject: Making rare earth magnets as good as alnico in signal output? Date: Tue, 4 Nov 1997 20:33:58 -0500 (EST) Hi group; I've noticed that here in Colorado, a number of electronic surplus stores have a variety of computer drive magnets. Most seem (its hard to always tell), to be the neodymium variety; with a sprinkling of older ferrous variety showing up. The neo variety are the most interesting due to their ~ 15k guass fields; although they are usually small and "wing" or "butterfly" shaped. For eddy current damping they are excellent in a "U" shaped iron/steel holder and are affixed to the inside upper part. The spacing must be close between the magnets. Regardless; for straight coil & magnet applications, it seems there is more of a signal (x5 - x10) from the older alnico magnets, which is presumably due to size/mass/broader flux field. Adding iron/steel helps space or broaden this guass field somewhat. I've tried afew varietys of magnet and iron designs but haven't found the right combinaton to make them approach even a small alnico in output signal from a coil. The question is,...........does anybody have a design or know of a WWW site, or reference to a book or magazine article that expounds on this "holy grail"? I'am probably missing the boat, or it left years ago; but it seems that the future supply of magnets for us may well be these critters, and making them much more useful. Thanks, Meredith _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Charles R. Patton" Subject: Re: Making rare earth magnets as good as alnico in signal output? Date: Tue, 04 Nov 1997 18:37:10 -0800 One thing to understand about these magnets is that the "butterfly" or half moon shaped magnets are most likely surplus from use in voice coil motors (head positioners) in hard disk drives for computers. As such, the magnetization is such that as you view it, it has two poles on its surface -- a North and a South. The voice coil is pyramidal or wedge shaped and the two sloped sides of the wedge will lie in the middle of the poles. If you were to use a coil which encompasses the whole magnet, you will effectively cancel out the induced voltage. To get an equivalent magnet, break the magnet in half lengthwise, now you will have two single-pole magnets. I.e., -------------------------------- | N N N N N N N S S S S S S S | | N N N N N N N S S S S S S S | | N N N N N N N S S S S S S S | | N N N N N N N S S S S S S S | -------------------------------- ^ | +--- Break here There are some exceptions to the above. If there are two individual segments mounted on the iron keeper, then each segment is a single pole as you would expect. The other technique would be to make a coil whose diameter is basically equal to the pitch of the poles in the magnet and lay it on the face--as it moves sideways, it will be very effective in generating voltage. Charles R. Patton, Editor, Geo-Monitor patton@......... MLamb12830@....... wrote: .... > variety of computer drive magnets.... > although they are usually small and "wing" or "butterfly" shaped. > ...but haven't found the right > combinaton to make them approach even a small alnico in output signal from a > coil. ... > Thanks, Meredith > > _____________________________________________________________________ > > 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: frankcnd@.......... (Frank Condon) Subject: Fontana Trend Date: Tue, 4 Nov 1997 19:31:34 -0800 (PST) Hello all: This morning there was another earthquake on what they consider to be the "Fontana Trend." It wasn't a huge earthquake, only 3.6 according to Caltech. However, it seems like every time another shock occurs it gets a little closer to the San Jacinto fault. This time it was less than 5 miles away. What does this tell us for the future? I have read the official publication about the proposed scenario for a major quake along this segment of the San Jacinto fault and it isn't pretty. Lots of infra-structure that could fail. Everything from major power grids to oil and gas pipelines that extend across the San Andreas just to the north of this location. It seems to me this area is a powder keg if and when it gets another big one. Between the Cucamonga, San Jacinto and the San Andreas faults this Fontana sequence gets on my nerves a little! Frank Condon mail to: frankcnd@.......... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: MLamb12830@....... Subject: Making rare earth magnets as good as alnico in signal output. Date: Wed, 5 Nov 1997 01:41:59 -0500 (EST) Hi group, Thank you Charles Patton for your reply. So,....basically these are 4 pole magnets; 2 N & 2 S poles, or 2 magnets in one unit. Is monolithic, the right word; my dictionary is dated 1962, so I don't know for sure. I do have a coil which I think will "do", for the moment. Its an old 1950's ~ Texas Instrument Rectiwriter pen motor coil which is rectangular & of the same width as the magnets; however the length is much longer. Its about 1500 ohms, but I have no way to measure its gauge wire. Also have several of these neo magnets. As I don't want to break these units, (they oxidize), so I think I'll keep them intact and go from there. To make it short, I just tried using 2 intact neo magnets with a square iron spacer located on the bottom third of each magnet and separating the two magnets. Yes,...it is the old "U" shape and upright, with the coil going between the the center and one side of the "U". Yes,....indeed, it worked swell! The voltage was about 20% more (1.8v compared to alnico of 1.4v max). This was per an unscientific hand movement of the coil. With a tighter spacing of the magnets, (risky for the magnets & coil), the voltage may go higher. The area of the coil covered by the neo magnets is only about one sixth of the area covered by the alnico. The deeper depth of the arrangement, also allows for more coil movement. With a "W" arrangement; with the coil centered over the "W" assembly it maybe an even stronger generator. This is all & good for coils with space in the center to accomodate parts of the magnet/iron. I haven't tried coils that fit in between the magnets. Goodby alnico............ Thanks,................Meredith _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Al Allworth Subject: Re: Making rare earth magnets as good as alnico in signal Date: Tue, 4 Nov 1997 23:35:37 -0800 (PST) At 06:37 PM 11/4/97 -0800, you wrote: >One thing to understand about these magnets is that the "butterfly" or Hello All, I have a small head drive assembly from a 3 1/2" hard drive that I am thinking of trying as a seismometer by attaching a weight where the heads were and tilting a little to provide restoring action (a near horizontal pendulum). It should work as a stromg motion device. Any comments? _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: MLamb12830@....... Subject: Making rare earth magnets as good as alnico in signal output? Date: Wed, 5 Nov 1997 03:25:24 -0500 (EST) Hi group; I've noticed that here in Colorado, a number of electronic surplus stores have a variety of computer drive magnets. Most seem (its hard to always tell), to be the neodymium variety; with a sprinkling of older ferrous variety showing up. The neo variety are the most interesting due to their ~ 15k guass fields; although they are usually small and "wing" or "butterfly" shaped. For eddy current damping they are excellent in a "U" shaped iron/steel holder and are affixed to the inside upper part. The spacing must be close between the magnets. Regardless; for straight coil & magnet applications, it seems there is more of a signal (x5 - x10) from the older alnico magnets, which is presumably due to size/mass/broader flux field. Adding iron/steel helps space or broaden this guass field somewhat. I've tried afew varietys of magnet and iron designs but haven't found the right combinaton to make them approach even a small alnico in output signal from a coil. The question is,...........does anybody have a design or know of a WWW site, or reference to a book or magazine article that expounds on this "holy grail"? I'am probably missing the boat, or it left years ago; but it seems that the future supply of magnets for us may well be these critters, and making them much more useful. Thanks, Meredith _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: GeE777@....... Subject: Fwd: ): MS announcement Date: Wed, 5 Nov 1997 07:46:51 -0500 (EST) In a message dated 97-11-04 20:35:45 EST, MLTCOLL writes: << Subject: MS announcement Microsoft Addresses Justice Department Accusations REDMOND, Wash. - Oct. 21, 1997 -- In direct response to accusations made by the Department of Justice, the Microsoft Corp. announced today that it will be acquiring the federal government of the United States of America for an undisclosed sum. It's actually a logical extension of our planned growth, said Microsoft chairman Bill Gates, It really is going to be a positive arrangement for everyone. Microsoft representatives held a briefing in the oval office of the White House with U.S. President Bill Clinton, and assured members of the press that changes will be minimal. The United States will be managed as a wholly owned division of Microsoft. An initial public offering is planned for July of next year, and the federal government is expected to be profitable by Q4 1999 at latest, according to Microsoft president Steve Ballmer. In a related announcement, Bill Clinton stated that he had willingly and enthusiastically accepted a position as a vice president with Microsoft, and will continue to manage the United States government, reporting directly to Bill Gates. When asked how it felt to give up the mantle of executive authority to Gates, Clinton smiled and referred to it as a relief. He went on to say that Gates has a proven track record, and that U.S. citizens should offer Gates their full support and confidence. Clinton will reportedly be earning several times the 200,000 annually he has earned as U.S. president, in his new role at Microsoft. Gates dismissed a suggestion that the U.S. Capitol be moved to Redmond as silly, though did say that he would make executive decisions for the U.S. government from his existing office at Microsoft headquarters. Gates went on to say that the House and Senate would of course be abolished. Microsoft isn't a democracy, he observed, and look how well we're doing. When asked if the rumored attendant acquisition of Canada was proceeding, Gates said, We don't deny that discussions are taking place. Microsoft representatives closed the conference by stating that United States citizens will be able to expect lower taxes, increases in government services and discounts on all Microsoft products. About Microsoft Founded in 1975, Microsoft (NASDAQ MSFT) is the worldwide leader in software for personal computers, and democratic government. The company offers a wide range of products and services for public, business and personal use, each designed with the mission of making it easier and more enjoyable for people to take advantage of the full power of personal computing and free society every day. About the United States Founded in 1789, the United States of America is the most successful nation in the history of the world, and has been a beacon of democracy and opportunity for over 200 years. Headquartered in Washington, D.C., the United States is a wholly owned subsidiary of Microsoft Corporation. The United States of America and Microsoft are registered trade marks of Microsoft Corporation. >> --------------------- Forwarded message: Subj: Fwd: ): MS announcement Date: 97-11-04 20:35:45 EST From: MLTCOLL To: HELDHI@....................... To: DANSIMPSN,PGJONES@........... To: JMAY@............................ To: Dactyle,RROCKWEL@................. To: glats2cu@........ To: jerald@............. --------------------- Forwarded message: Subj: Fwd: ): MS announcement Date: 97-11-04 17:42:35 EST From: JackCeram To: BBUTEK,Airplayn@............. To: Negrych@...................... To: BillPayne,Silbond@................ To: JReents@........ To: KGaughan@............... To: ASalamat@......................... To: MVRUBIN,102421.3464@.............. To: SFisher@............ To: Stratton_Tom@....................... To: Gnels,J3L1Ferr@....... To: bobeangi@..................... To: LAMemm@.......................... To: MLTCOLL,GWimsatt@............ To: DrDave.Norris@........ To: Pelican@....................... To: WS-FELS@........... --------------------- Forwarded message: From: gdula@.......... (Bob Gdula) To: stella1@.......... (Stella Gdula), "Jackceram@......."@.......... Date: 97-11-03 12:27:00 EST Robert A. Gdula , Ph.D. Interface and Surface Science Materials Laboratory IBM Storage Systems Division San Jose, CA USA (408) 256-0316 e-mail internal: Bob Gdula/San Jose/IBM@IBMUS internet: gdula@.......... ---------------------- Forwarded by Bob Gdula/San Jose/IBM on 11-03-97 09:16 AM --------------------------- Alan Spool 11-03-97 08:43 AM To: sjevm5.ghaderi@vm, sjevm5.prime@vm, sjevm5.byork@vm, almvma.legg@vm, sjevm5.mparker@vm, Catherine E Albrecht/San Jose/IBM@IBMUS, Malika Carter/San Jose/IBM@IBMUS, Joel Forrest/San Jose/IBM@IBMUS, Mariano Garces/San Jose/IBM@IBMUS, Charles Hignite/San Jose/IBM@IBMUS, William S Morrison/San Jose/IBM@IBMUS, Phil Peterson/San Jose/IBM@IBMUS, Dennis Ramos/San Jose/IBM@IBMUS, Alan Spool/San Jose/IBM@IBMUS, Regina Strener/San Jose/IBM@IBMUS, Gloria Washington/San Jose/IBM@IBMUS, Gina Whitney/San Jose/IBM@IBMUS, Kathy Kuboi/San Jose/IBM@IBMUS, Deborah Yaney/San Jose/IBM@IBMUS, Ron Herbold/San Jose/IBM@IBMUS, John Burns/San Jose/IBM@IBMUS, Cynthia Delenia/San Jose/IBM@IBMUS, Thomas Blackburn/San Jose/IBM@IBMUS, Daryl Pocker/San Jose/IBM@IBMUS, Mike Baldwin/San Jose/IBM@IBMUS, Elizabeth Brinkman/San Jose/IBM@IBMUS, Joel Caharian/San Jose/IBM@IBMUS, Wendy Chung/San Jose/IBM@IBMUS, Bob Gdula/San Jose/IBM@IBMUS, Katherine Ledesma/San Jose/IBM@IBMUS, Heidi Merkins/San Jose/IBM@IBMUS, Renata Vedder/San Jose/IBM@IBMUS, Joel Lai/San Jose/IBM@IBMUS, Garvin Stone/San Jose/IBM@IBMUS, Monica Vargas/San Jose/IBM@IBMUS, Richard Stover/San Jose/IBM@IBMUS, Frederick Eng/San Jose/IBM@IBMUS, Mark Powell/San Jose/IBM@IBMUS, Thomas Shatz/San Jose/IBM@IBMUS, Jane Kraus/San Jose/IBM@IBMUS, David Scott/San Jose/IBM@IBMUS, Owen Melroy/Almaden/IBM@ALMADEN @ IBM_INTERNAL cc: Subject: ): MS announcement FYI ---------------------- Forwarded by Alan Spool/San Jose/IBM on 11/03/97 08:42 AM --------------------------- guppymom@........ on 10/31/97 08:26:10 PM Please respond to guppymom@........ @ internet To: plant1.pcnet.net.com!ke3147@........... @ internet, Nsmereski@....... @ internet, Imthetaxmn@....... @ internet, Alan Spool/San Jose/IBM@IBMUS, Beutboni@........... @ internet, wsattler@........... @ internet, joe_mckeon@.......... @ internet, Mike_mcintyre@.......... @ internet, Tak843@....... @ internet, L82school@........ @ internet, pkipnis@............. @ internet, askal@........ @ internet, Otto_hovorka@.................... @ internet, mgustafson@........... @ internet, burt_gustaf@....... @ internet, elaine_chung@........... @ internet, brionese@.............. @ internet cc: Subject: ): MS announcement Subject: MS announcement Microsoft Addresses Justice Department Accusations REDMOND, Wash. - Oct. 21, 1997 -- In direct response to accusations made by the Department of Justice, the Microsoft Corp. announced today that it will be acquiring the federal government of the United States of America for an undisclosed sum. It's actually a logical extension of our planned growth, said Microsoft chairman Bill Gates, It really is going to be a positive arrangement for everyone. Microsoft representatives held a briefing in the oval office of the White House with U.S. President Bill Clinton, and assured members of the press that changes will be minimal. The United States will be managed as a wholly owned division of Microsoft. An initial public offering is planned for July of next year, and the federal government is expected to be profitable by Q4 1999 at latest, according to Microsoft president Steve Ballmer. In a related announcement, Bill Clinton stated that he had willingly and enthusiastically accepted a position as a vice president with Microsoft, and will continue to manage the United States government, reporting directly to Bill Gates. When asked how it felt to give up the mantle of executive authority to Gates, Clinton smiled and referred to it as a relief. He went on to say that Gates has a proven track record, and that U.S. citizens should offer Gates their full support and confidence. Clinton will reportedly be earning several times the 200,000 annually he has earned as U.S. president, in his new role at Microsoft. Gates dismissed a suggestion that the U.S. Capitol be moved to Redmond as silly, though did say that he would make executive decisions for the U.S. government from his existing office at Microsoft headquarters. Gates went on to say that the House and Senate would of course be abolished. Microsoft isn't a democracy, he observed, and look how well we're doing. When asked if the rumored attendant acquisition of Canada was proceeding, Gates said, We don't deny that discussions are taking place. Microsoft representatives closed the conference by stating that United States citizens will be able to expect lower taxes, increases in government services and discounts on all Microsoft products. About Microsoft Founded in 1975, Microsoft (NASDAQ MSFT) is the worldwide leader in software for personal computers, and democratic government. The company offers a wide range of products and services for public, business and personal use, each designed with the mission of making it easier and more enjoyable for people to take advantage of the full power of personal computing and free society every day. About the United States Founded in 1789, the United States of America is the most successful nation in the history of the world, and has been a beacon of democracy and opportunity for over 200 years. Headquartered in Washington, D.C., the United States is a wholly owned subsidiary of Microsoft Corporation. The United States of America and Microsoft are registered trade marks of Microsoft Corporation. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Roseberry Subject: Re: Making rare earth magnets as good as alnico in signal output? Date: Wed, 05 Nov 1997 09:20:42 -0600 Charles R. Patton wrote: > ... break the magnet in half lengthwise, now you will > have two single-pole magnets. I.e., > > -------------------------------- > | N N N N N N N S S S S S S S | > | N N N N N N N S S S S S S S | > | N N N N N N N S S S S S S S | > | N N N N N N N S S S S S S S | > -------------------------------- > ^ > | > +--- Break here > Mr. Patton: I'm puzzled. Are you suggesting that when a bar magnet is divided, one piece becomes a "South" monopole; the other a "North" monopole? If so, that would undermine almost everything I have come to understand about magnets, in particular, their internal structure. Regards, Michael J. Roseberry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "James M Hannon" Subject: Re: Making rare earth magnets as good as alnico in signal output? Date: Wed, 5 Nov 1997 09:38:23 -0600 I don't think that is what he meant. It is hard to communicate some of these things without good pictures. With the magnets in question the opposite pole is on the back side of the magnet. So when you break it instead of having a magnet with 4 poles you get two magnets with two poles. Jim Hannon mjr@........ on 11/05/97 09:20:42 AM Please respond to psn-l@............. To: psn-l@............. cc: (bcc: James M Hannon/CedarRapids/Collins/Rockwell) Subject: Re: Making rare earth magnets as good as alnico in signal output? Charles R. Patton wrote: > ... break the magnet in half lengthwise, now you will > have two single-pole magnets. I.e., > > -------------------------------- > | N N N N N N N S S S S S S S | > | N N N N N N N S S S S S S S | > | N N N N N N N S S S S S S S | > | N N N N N N N S S S S S S S | > -------------------------------- > ^ > | > +--- Break here > Mr. Patton: I'm puzzled. Are you suggesting that when a bar magnet is divided, one piece becomes a "South" monopole; the other a "North" monopole? If so, that would undermine almost everything I have come to understand about magnets, in particular, their internal structure. Regards, Michael J. Roseberry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: GeE777@....... Subject: Re: Fontana Trend Date: Wed, 5 Nov 1997 11:35:09 -0500 (EST) In a message dated 97-11-05 01:46:29 EST, frankcnd@.......... writes: << This morning there was another earthquake on what they consider to be the "Fontana Trend." It wasn't a huge earthquake, only 3.6 according to Caltech. >> Please note the map in- http://quake.wr.usgs.gov/recenteqs/ as of this date. There is a series of small events circumventing the ''locked area'' of the San Andreas Fault to the northeast. These series of small events leave the area of the San Andreas Fault in the Fontana area and return to the San Andreas in the Parkfield area. George Erich GeE777@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jim Bone Subject: Re: Fontana Trend Date: Wed, 05 Nov 1997 14:49:23 -0800 GeE777@....... wrote: > > In a message dated 97-11-05 01:46:29 EST, frankcnd@.......... writes: > > << This morning there was another earthquake on what they consider to be the > "Fontana Trend." It wasn't a huge earthquake, only 3.6 according to Caltech. > >> > > Please note the map in- > http://quake.wr.usgs.gov/recenteqs/ > > as of this date. > > There is a series of small events circumventing the ''locked area'' of the > San Andreas Fault to the northeast. These series of small events leave the > area of the San Andreas Fault in the Fontana area and return to the San > Andreas in the Parkfield area. > > George Erich > GeE777@....... > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L Could you be more specific?? A list of point might be helpful in visualizing the trend you are describing. Thanks in advance. Jim Bone _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: lahr@................. (Dr. John Lahr (USGS-GI Seismologist)) Subject: seismometers need good home Date: Wed, 5 Nov 1997 17:27:59 -0900 Hi John, I wonder if the Smithsonian would be interested in these instruments? JCLahr ################################## John C. Lahr ################################# Seismologist ################################ U.S. Geological Survey ############################### Geologic Hazards Team ############################## 1711 Illinois Street ~~~~~~~~~~~~~~ Get ~~~~~~~~~~ ############################# ########################################################### Golden, Colorado 80401 ################################ Phone: (303) 273-8596 ################################# Fax: (303) 273-8600 ~~~~~~~~ the thrust? ~~~~~~~~~~~~~ lahr@........ #################################### http://www.aeic.alaska.edu/lahr > From bulkmail@................... Wed Nov 5 16:12:41 1997 > Date: Wed, 5 Nov 97 17:15:59 PST > From: Bulkmail System > Subject: WWSSN Seismometers Available > > WWSSN Seismometers Available > > I would like these instruments to get a good home where, ideally, they can > be set up and used to record earthquakes as they were intended to be used. > > These are examples of the original Sprengnether WWSSN seismometers > which collected much of the original seismological data that led to the > acceptance of plate tectonics. As such they have some historical value. > > These, however, are working instruments. They require a rather large area > to set up and moderate-to-good temperature control to operate reliably. > Thus they are not suitable as "field" instruments. Probably, some university > that is looking to get a station operating for research and teaching is the > ideal candidate to gets these instruments. > > I will be glad to help get them to who ever can use them. I have limited > knowledge of setting them up, but have a set of manuals. The gaining > institution will have to pay shipping charges, which should be minor. The > instruments are large in volume, but not particularly heavy. > > These instruments are on loan from the USGS to the Air Force. I have the > USGS-to-AF transfer paperwork, so the "title" is clear. > > My address is: > > John Cipar > Air Force Research Laboratory > Hanscom AFB, MA > 617-377-3767 > cipar@.......... > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "David A. Nelson" Subject: Re: seismometers need good home Date: Thu, 06 Nov 1997 16:13:30 +1200 John, these are an awesome seismometer and ther do weigh a lot ~30+ lbs for someone who doesn't want to build a LP lehman this would be an excellect choice I have one here at home that will be uop and unning as soon as the concrete pad can be laid and styrofoam housing organised. The Sprengnether or Press-Ewing, as it was originally known as has an adjustable period from ~12 to 45 seconds (up to 60 sec if you can place it in a very low noise site and keep the temperature very stable. Dave At 05:27 PM 11/5/97 -0900, you wrote: >Hi John, >I wonder if the Smithsonian would be interested in these instruments? >JCLahr >> Date: Wed, 5 Nov 97 17:15:59 PST >> From: Bulkmail System >> Subject: WWSSN Seismometers Available >> WWSSN Seismometers Available >> I would like these instruments to get a good home where, ideally, they can >> be set up and used to record earthquakes as they were intended to be used. >> These are examples of the original Sprengnether WWSSN seismometers >> which collected much of the original seismological data that led to the >> acceptance of plate tectonics. As such they have some historical value. >> These, however, are working instruments. They require a rather large area >> to set up and moderate-to-good temperature control to operate reliably. >> Thus they are not suitable as "field" instruments. Probably, some university >> that is looking to get a station operating for research and teaching is the >> ideal candidate to gets these instruments. >> I will be glad to help get them to who ever can use them. I have limited >> knowledge of setting them up, but have a set of manuals. The gaining >> institution will have to pay shipping charges, which should be minor. The >> instruments are large in volume, but not particularly heavy. >> >> These instruments are on loan from the USGS to the Air Force. I have the >> USGS-to-AF transfer paperwork, so the "title" is clear. >> >> My address is: >> >> John Cipar >> Air Force Research Laboratory >> Hanscom AFB, MA >> 617-377-3767 >> cipar@.......... >> > >_____________________________________________________________________ > >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: owl@................. Subject: Is Your Web Site A Secret? Date: Wed, 5 Nov 1997 23:13:32 -0500 (EST) Is your web site the best kept secret on the Internet? We'll promote it to 50 search engines and indexes for $85 and complete the job in 2 business days. Satisfaction is guaranteed! If you have a great product, but are not getting many inquiries from your Web site, you may not be adequately listed on the Web's search engines and indexes. Millions of viewers daily use these facilities to find the products and services they are looking for. But if your site is not listed, no one will see it. Listings on most of these services are free. However, locating and filling out the forms required to get a listing can take several days, and most people just don't have the time to do it. That is why we offer a web site promotion service. WHAT'S THE DEAL? We will submit your site to 50 indexes and search engines for $85. We will accept the return of this E-mail, with the form below filled out, as an order. We will bill you upon completion of the promotion. Our terms are net 15 days from date of invoice. Satisfaction guaranteed! HOW LONG WILL IT TAKE? Generally, we complete the submissions within 48 hours of receiving your order. It can take any individual search engine or index up to three weeks to process your submission, although most are much faster. WHAT SEARCH ENGINES AND INDEXES ARE INCLUDED IN THE PROMOTION? The list changes from time to time. This is our current list: Alta Vista, BC Internet, BizCardz Business Directory, BizWeb, Excite, Galaxy, HotBot, Infoseek, InfoSpace, Jayde Online Directory, JumpCity JumpLink, Linkcentre Directory, LinkMonster, Lycos, Magellan, Manufacturers Information Network, Net Happenings, Net Mall, Net-Announce, New Page List, New Riders WWW Yellow Pages, Northern Light, One World Plaza, Open Text Web Index, PageHost A-Z, PeekABoo, Project Cool, Scrub The Web, Seven Wonders, Sserv, Starting Point, The Galactic Galaxy, The Weekly Bookmark, True North,TurnPike, Unlock:The Information Exchange, Web 100, Web Crawler, Web Walker, Web World Internet Directory, WebVenture Hotlist, What's New, WhatUSeek, Where2Go, World Wide Business Yellow Pages, Wow! Web Wonders!, WWW Worm, YelloWWWeb, Your WebScout HOW WILL I KNOW THAT YOU HAVE PROMOTED MY SITE? When we have completed the promotion, we will send you an HTML file as an attachment to your E-mail bill. Save this file to your disk, and view it through your Web browser. It provides links to the search engine we submitted your site to, plus any comments we received from them when we did it. ARE THERE ANY GUARANTEES? We do not require prepayment. Your satisfaction is guaranteed or you don't pay the bill. WHO IS OWL'S EYE PRODUCTIONS? We are a web site promotion company located at: Owl's Eye Productions, Inc. 260 E. Main Street Brewster, NY 10509 Phone: (914) 278-4933 Fax: (914) 278-4507 Email: owl@................. HOW DO I ORDER? The easiest way to order is by e-mail. Just hit the REPLY button on your e-mail program and fill out the following information. (This information will be posted to the search engines/indexes): Your name: Company Name: Address: City: State/Prov: Zip/Postal Code: Telephone: Fax: Email address: URL: http:// Site Title: Description (about 25 words): Key words (maximum of 25, in descending order of importance): Proofs (Where shall we e-mail proofs): If billing a different address, please complete the following: Addressee: Company Name: Address: City: State/Prov: Zip/Postal Code: Telephone: Fax: Email address: We will bill via Email. (SE7O22) Terms: By returning this document via Email, you agree as follows: You have the authority to purchase this service on behalf of your company. Terms are net 15 days. Accounts sent to collections will be liable for collection costs. You agree to protect and indemnify Owl's Eye Productions, Inc. in any claim for libel, copyright violations, plagiarism, or privacy and other suits or claims based on the content or subject matter of your site. WHAT HAPPENS NEXT? When we receive your order, we will input the information into our system, and send you a proof. After we process any corrections, we will run your promotion, capturing any comments from search engines as we go. We will incorporate these into an HTML-formatted report to you, which we will attach to your bill. ===Web Promotions=====Press Releases=====Link Exchanges========= Owl's Eye Productions, Inc. 260 E. Main Street Brewster, NY 10509 Ph: 914-278-4933 Fx: 914-278-4507 E-mail: owlseye@................. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Mark Wilson mark@.............." Subject: Re: Is Your Web Site A Secret? Date: Wed, 5 Nov 1997 20:48:43 -0800 (PST) Doesn't this stuff just irritate you to no end? *********************************************************************** --- mark@.............. --- http://www.markwilson.com --- wilsonm@............ *********************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: prewar Subject: Re: seismometers need good home Date: Thu, 06 Nov 1997 14:42:39 +0000 David A. Nelson wrote: > these are an awesome seismometer and ther do weigh a lot ~30+ lbs... .....snip..... Hi Dave, Many years ago, before we were both born (!), the moving mass of seismometers could weigh over 20 TON!!.....the 'Wiechert' monster in Europe was such a beastie. It used mechanical levers, coupled from the 20 ton mass, to the pen and gave a magnification of some 2000! Regards, Albert Noble (England). _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Larry P. Thomas WA0GWA" Subject: Re: Is ... Secret? What's a person to do! Date: Thu, 06 Nov 1997 08:53:00 -0600 >Doesn't this stuff just irritate you to no end? > >*********************************************************************** > --- mark@.............. > --- http://www.markwilson.com > --- wilsonm@............ >*********************************************************************** Sure does. I get it on every SIG I follow but there seems to be no real way of stopping it. I just keep hitting the "Delete" key. I ususally don't even comment on any of it. Some of the SIG's I follow are extremely sensitive (i.e. have a lot really rude people on them) and even simple comments start never ending threads. This PSN SIG is the best SIG I follow when it comes to tolerance. Wish all the SIG's I followed were as good as this one. Thanks Larry wa0gwa ----------------------------------------------------------------------- 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: Marnie Gannon Subject: Canadian quake Date: Thu, 06 Nov 1997 11:44:06 -0700 You can find reports, locations and waveforms for the Canadian quake at: http://www.seismo.nrcan.gc.ca/eq_report.html Interestingly, there was a 4.7 in the area on Oct.28. Good site, with history of larger quakes: "Charlevoix - Kamouraska (CHV) an area 100km downriver from Quebec City. This is the most seismically active and most closely monitored region in eastern Canada. In 1925 an earthquake believed to be M7 occurred in the St. Lawrence valley near La Malbaie. This event caused extensive damage, particularly to communities along the banks of the river. Historical accounts describe the effects of three other earthquakes greater than M6 that occurred in this zone (1663, 1860 and 1870)." Marnie Gannon _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "James M Hannon" Subject: Lehman coil and magnet Date: Thu, 6 Nov 1997 14:43:40 -0600 The recent discussion of using hard drive magnets generated a question in my mind. Has anyone thought of or tried using a current input preamp rather than a voltage input preamp for the coil? In theory this should allow the use of a coil with fewer turns and still get the same level or larger out of the preamp. Having a coil with fewer turns would in turn make it easier to use the smaller magnets and a narrower gap which would also increase the output. Jim Hannon _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: GeE777@....... Subject: Eastern Sierra Nevada Quakes Date: Thu, 6 Nov 1997 16:56:27 -0500 (EST) Los Angeles Times, Nov 6, 1997 By Kenneth Reich NEXT STORY This week's moderately strong temblors in western Nevada could be=20 connected to a quake swarm about 30 miles away east of Mammoth Lakes,=20 scientists monitoring volcanic earthquakes near Mammoth said Wednesday.=20 =A0=A0=A0=A0=A0The U.S. Geological Survey reported 34 quakes of magnitude= 3.0 or=20 greater in California and Nevada this past week--an unusually high=20 number--including 24 in Nevada and five at Mammoth Lakes.=20 =A0=A0=A0=A0=A0Other quakes of this magnitude have occurred in such widel= y=20 separate areas as San Clemente Island and near Quincy in Northern=20 California. The latter quake, which occurred at 9:49 a.m. Wednesday, was=20 felt as far away as Sacramento. It was first measured at magnitude 4.8=20 but was later downgraded to 4.3. A 4.5 quake also occurred Wednesday=20 afternoon 30 miles southeast of Bishop, Calif.=20 =A0=A0=A0=A0=A0The seismic events in Nevada included quakes of magnitudes= 5.3,=20 4.8, 4.3 and 4.2 in a remote mountainous area.=20 =A0=A0=A0=A0=A0Hundreds of smaller quakes--the strongest was 3.4--have oc= curred=20 along the same northeast-southwest lineal alignment near the eastern=20 Sierra town of Mammoth Lakes.=20 =A0=A0=A0=A0=A0Scientists said there is no connection between the San Cle= mente=20 Island quake and the Quincy quake. But they viewed the Mammoth and=20 Nevada quakes differently.=20 =A0=A0=A0=A0=A0David Hill of the Geological Survey, the chief monitor of = volcanic=20 precursors in the Mammoth region, said that scientific monitoring of=20 Mammoth has increased since June in the wake of repeated swarms of=20 quakes, some increased ground uplift and small changes in hot springs.=20 =A0=A0=A0=A0=A0"We are certainly watching things more closely now," Hill = said.=20 "But . . . there is no evidence that things are moving toward [an=20 eruption in the short term]."=20 =A0=A0=A0=A0=A0Hill said that research into "sympathetic" earthquakes in = the=20 eastern Sierra after the comparatively distant Landers quake of 1992=20 could mean there is a possible connection between the Nevada and Mammoth=20 quakes.=20 =A0=A0=A0=A0=A0Ross Stein, another Geological Survey scientist, said, "Ma= mmoth is=20 basically straining the whole area, and quakes that have taken place=20 north of Bishop in the Chalfant Valley and in Nevada over the last 15 to=20 20 years could be related."=20 =A0=A0=A0=A0=A0He added: "This week the San Andreas fault [closer to the = Pacific]=20 seems to be sleeping, and what is known as the Eastern California Shear=20 Zone has been active. In that respect, he said, even the Quincy quake=20 [which is along the shear zone] could be connected to Mammoth."=20 =A0=A0=A0=A0=A0Allan Lindh, a former director of Geological Survey earthq= uake=20 research for the Western states, said, "We know from what happened after=20 Landers that there are long-distance connections between quakes.=20 =A0=A0=A0=A0=A0"The Nevada quakes in the Great Basin are related to volca= nic=20 processes," he said. "Probably all of this is related, we just don't=20 know exactly how."=20 =A0=A0=A0=A0=A0Chris Farrar, another monitor of Mammoth, said he believes= =20 scientific concern about a Mammoth eruption would rise "if the=20 deformation keeps going on at its current rate and moves into a=20 shallower depth."=20 =A0=A0=A0=A0=A0But Hill said: "We don't see any short-term, localized def= ormation=20 that might be associated with magma [molten rock] moving into the=20 shallower crust."=20 =A0=A0=A0=A0=A0Hill, Farrar and another survey specialist, Michael Sorey,= said=20 they have looked intensively into reports of recent changes in hot=20 springs near Mammoth. But they have not been able to establish any=20 overall increase in hot water emissions, which could be caused by=20 injections of magma into the ground water system.=20 _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Roseberry Subject: X9 Flare and Proton Event Date: Thu, 06 Nov 1997 19:51:48 -0600 Group: I realize this is a little off-subject. Possibly some of you have magnetometers (search coils were a subject of interest on this list last year), well if you do get ready! Our sun emitted a REALLY hugh flare this morning (see attachment); the next few days should be interesting for mag field watchers. Hope this info is not unwelcome on the list, if so, let me know. Regards, Michael J. Roseberry Hi Ron, Hal (New Millenium) has okayed my posting this....a new flare this morning. Regards, Nancy Hugo ---------- Forwarded message ---------- Date: Thu, 06 Nov 1997 11:18:03 -0500 From: New Millennium Subject: **X9 Flare and Proton Event** 11.06.97/1530 UTC X9 Flare and Proton Event 11.06.97 1530 UTC Wow! At approximately 1200 UTC (7am EST) this morning an ~X-9~ class flare was recorded by the solar measuring equipment used by NASA and SEC. Within 30 minutes an intense Proton flare event began at the GOES satellites as well. The massive flare that occurred on the 4th and has brought all the watches and anticipated magnetic storming (Nov 6-7-8) was an X-1 class flare. This mornings flare was an X-9, the ~very~ highest rating on the intensity scale for measuring the power output of solar flares. Just as the Xray signature of this new flare was much more powerful than Nov.4th's event, so was the Proton event that has followed. This is a difficult concept to grasp, but the energy released from this morning's X-9 flare was 100 million times more than with Tuesday's X-1 flare. Each number on the flare scale represents a tenfold increase in energy output of the event; As an example, an X-2 is ten times more powerful than an X-1. If the alignment of the event was "geoeffective" (in good position relative to Earth) then we can expect a truly massive electron cloud and geomagnetic event sometime between the 8th and the 10th. According to NASA, the famous geomagnetic storm of 1989 came after a series of flares-the most powerful of which was an X-5; Obviously this event has the ~potential~ to be much much more powerful. Today is the first day of the original series of magnetic storm watches. Obviously there will be a new series of severe magnetic storm watches issued for the 8th through the 10th... longer if the solar events continue. As soon as more detailed information is available on this morning's incredible event, I will send it out via email bulletins. From: Al Allworth Subject: Potential Geomagnetic Storm Warning Date: Thu, 6 Nov 1997 18:03:10 -0800 (PST) >X-Sender: caschue@...................... >Date: Thu, 06 Nov 1997 12:25:31 -0500 >To: Al - W7PXX , > Ed Bathgate RMA Repair Dept , > Bruce Erkkila-KC5OV , > Bruce Erkkila-KC5OV , > Don Hillger , > John K 5 J J , > "Jerry L. Rowe" , > Gary Shay , > Gary Barr-WA6TWT , > Richard Barth-W3HWN , > Dan Bathker , > Don Bennett-N7TF , > Shayla Taylor-KA5PRZ , > Felipe Arroyo , > Dick Foster , Bob Foster , > Muse Mann , > David Maples-WB4FUR , > Bill Notley-KD6ZXI , > Paul Robbins-KC6ZLW, > Steve Schindler-WD4MJJ, > "W. Russell Slye" , > Steve Veader , W6VPH , > H F WRIGHT , > Ron Grandmaison , > N V Pollack-KA3ENO , > Fred Fredlock-N4KVN , > Michael Cauley , > Marv Storey , > Steve Wnuk , > AA1BU , > AA2NN , K4VV , > K9ICF , > KC1SE , > KE7UA , N1OJ0 , > W1TCF , > W8XO , > WG3A , WN3X , > WX2S , > "Robert A. Kile-KG7D" , > EDMOND BRADY , > Zeke , > , , > Albert H Zimmerman-W8UYN , > "Paul J. Poling-N8CKG" >From: henry schuett >Subject: Potential Geomagnetic Storm Warning >Cc: Roberto.J.Acosta@.............. Godfrey.Anzic@.............. > Terry.L.Bell@.............. Joseph.M.Berki@.............. > Bruce.L.Bream@.............. Michael.A.Cauley@.............. > Donald.E.Costello@.............. William.T.Dedula@.............. > Douglas.C.Dolch@.............. Alan.N.Downey@.............. > Patrick.W.Dunn@.............. Michael.W.Goin@.............. > Raiford.E.Hann@.............. Don.R.Hilderman@.............. > Thomas.J.Hill@.............. Louis.R.Ignaczak@.............. > Kenneth.A.Jensen@.............. Brad.W.Kaustinen@.............. > David R Kifer , > Ihor.Kramarchuk@.............. Steven.W.Mainger@.............. > Joseph.Maziarz@.............. James.H.McKim@.............. > Robert.C.Mate@.............. Steven.W.ODonnell@.............. > Richard.L.Patterson@.............. William.J.Rieke@.............. > Michael.A.Robertson@.............. Noel.B.Sargent@.............. > Richard.R.Scheske@.............. Philip.A.Stehno@.............. > Russell.E.Steinbach@.............. William.H.Stokes@.............. > Steven.J.Struharik@.............. Daniel.M.Vento@.............. > Lawrence.W.Wald@.............. > KC8F , > Stephen.P.Wnuk@.............. 71026.1561@............... > Glenn L Williams , > kc4iyd@....................... > Nancy Rabel Hall , > Greg Romaniak-N8XOS, > Earl-N7BYL > >Subject: Potential Geomagnetic Storm Warning >>Date: Wed, 5 Nov 1997 13:31:01 -0500 >> >> >>Potential Geomagnetic Storm Warning >> >> (See Appended Comments for Synoptic Information) >> >> HIGH RISK PERIOD: 06 - 07 NOV (UT days) >>MODERATE RISK PERIOD: 05 - 08 NOV >> >> >>POTENTIAL LOW-MIDDLE LATITUDE STORM INTENSITY: MAJOR >> POTENTIAL HIGH LATITUDE STORM INTENSITY: MAJOR TO SEVERE >> >> >> POTENTIAL DURATION OF GEOMAGNETIC STORM: APPROX 48 HOURS >> DURATION OF MAIN BELT OF ACTIVITY: APPROX 24 HOURS ON 07 >>NOV >> >> >>POTENTIAL PEAK LOW-MIDDLE LATITUDE K-INDEX VALUES: 8 >> POTENTIAL PEAK HIGH LATITUDE K-INDEX VALUES: 9 >> >> >> EXPECTED DOMINATING LOW-MIDDLE LATITUDE K-INDEX: 5 TO 6 >> EXPECTED DOMINATING HIGH LATITUDE K-INDEX: 6 >> >> >> POTENTIAL FOR LOW LATITUDE HF DEGRADATION: MODERATE >> POTENTIAL SEVERITY OF HF DEGRADATION: STRONG MINOR >> EXPECTED HF PROPAGATION CONDITIONS: FAIR >> >> >>POTENTIAL FOR MIDDLE LATITUDE HF DEGRADATION: VERY HIGH >> POTENTIAL SEVERITY OF HF DEGRADATION: MAJOR >> EXPECTED HF PROPAGATION CONDITIONS: POOR TO USELESS >> >> >> POTENTIAL FOR HIGH LATITUDE HF DEGRADATION: VERY HIGH >> POTENTIAL SEVERITY OF HF DEGRADATION: MAJOR >> EXPECTED HF PROPAGATION CONDITIONS: VERY POOR TO FREQ. >>USELESS >> >> >>POTENTIAL RISK FOR GEOSYNCHRONOUS MAGNETOPAUSE CROSSINGS: 60PROBABLE >> >> >>SUSPECTED SOURCE OF OBSERVED/EXPECTED ACTIVITY: >>A series of coronal mass ejections. The last one observed on 04 >>November >>that was associated with the major X-class proton flare is expected to >>produce a major to severe geomagnetic storm on 07 November. >> >> >>--------------------------------- >>--------------------------------- >>EST. POTENTIAL GEOMAGNETIC IMPACT EST. POTENTIAL IONOSPHERIC >>IMPACT >>--------------------------------- >>--------------------------------- >> SEVERE STORM : 25 LOW LATITUDES : STRONG MINOR >> MAJOR STORM : 40 MIDDLE LATITUDES : MAJOR >> MINOR STORM : 30 HIGH LATITUDES : MAJOR >> ACTIVE OR LESS : 05 POLAR LATITUDES : MAJOR >>--------------------------------- >>--------------------------------- >> PROBABLE SI ASSOCIATION : 90 ESTIMATED GLOBAL IMPACT: MAJOR >> >> >>ESTIMATED FORECAST PEAK PLANETARY 24-HOUR A-INDEX DURING STORM: 55 TO 70 >> ---- --------------- >> >> >>COMMENTS: >> >> >> Activity is expected to begin primarily on 06 November with the >>arrival >>of one of the coronal mass ejections related to one of the stronger >>minor >>M-class flares observed. This activity could result in periods of minor >>to >>major geomagnetic storming on 06 November. The largest disturbance is >>expected to arrive with a fairly vigorous shock-front on 07 November and >>produce periods of major to severe geomagnetic storming. Currently, the >>activity on 07 November is expected to reach or exceed major storm >>levels. >>A return to quieter levels of activity is not expected until later on 08 >>November, barring further solar outbursts. >> >> >> A middle latitude auroral activity warning has been issued as well >>as a >>low latitude auroral activity watch for 06 and 07 November. Consult the >>web >>page at: http://solar.uleth.ca/solar/www/aurpred.html for supporting >>graphics >>forecasts. >> >>** End of Warning ** > > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Al Allworth Subject: Solar Cycle Status Report Date: Thu, 6 Nov 1997 18:03:31 -0800 (PST) >X-Sender: caschue@...................... >Date: Thu, 06 Nov 1997 12:27:40 -0500 >To: Al - W7PXX , > Ed Bathgate RMA Repair Dept , > Bruce Erkkila-KC5OV , > Bruce Erkkila-KC5OV , > Don Hillger , > John K 5 J J , > "Jerry L. Rowe" , > Gary Shay , > Gary Barr-WA6TWT , > Richard Barth-W3HWN , > Dan Bathker , > Don Bennett-N7TF , > Shayla Taylor-KA5PRZ , > Felipe Arroyo , > Dick Foster , Bob Foster , > Muse Mann , > David Maples-WB4FUR , > Bill Notley-KD6ZXI , > Paul Robbins-KC6ZLW, > Steve Schindler-WD4MJJ, > "W. Russell Slye" , > Steve Veader , W6VPH , > H F WRIGHT , > Ron Grandmaison , > N V Pollack-KA3ENO , > Fred Fredlock-N4KVN , > Michael Cauley , > Marv Storey , > Steve Wnuk , > AA1BU , > AA2NN , K4VV , > K9ICF , > KC1SE , > KE7UA , N1OJ0 , > W1TCF , > W8XO , > WG3A , WN3X , > WX2S , > "Robert A. Kile-KG7D" , > EDMOND BRADY , > Zeke , > , , > Albert H Zimmerman-W8UYN , > "Paul J. Poling-N8CKG" >From: henry schuett >Subject: Solar Cycle Status Report >Cc: Roberto.J.Acosta@.............. Godfrey.Anzic@.............. > Terry.L.Bell@.............. Joseph.M.Berki@.............. > Bruce.L.Bream@.............. Michael.A.Cauley@.............. > Donald.E.Costello@.............. William.T.Dedula@.............. > Douglas.C.Dolch@.............. Alan.N.Downey@.............. > Patrick.W.Dunn@.............. Michael.W.Goin@.............. > Raiford.E.Hann@.............. Don.R.Hilderman@.............. > Thomas.J.Hill@.............. Louis.R.Ignaczak@.............. > Kenneth.A.Jensen@.............. Brad.W.Kaustinen@.............. > David R Kifer , > Ihor.Kramarchuk@.............. Steven.W.Mainger@.............. > Joseph.Maziarz@.............. James.H.McKim@.............. > Robert.C.Mate@.............. Steven.W.ODonnell@.............. > Richard.L.Patterson@.............. William.J.Rieke@.............. > Michael.A.Robertson@.............. Noel.B.Sargent@.............. > Richard.R.Scheske@.............. Philip.A.Stehno@.............. > Russell.E.Steinbach@.............. William.H.Stokes@.............. > Steven.J.Struharik@.............. Daniel.M.Vento@.............. > Lawrence.W.Wald@.............. > KC8F , > Stephen.P.Wnuk@.............. 71026.1561@............... > Glenn L Williams , > kc4iyd@....................... > Nancy Rabel Hall , > Greg Romaniak-N8XOS, > Earl-N7BYL > >Subject: Solar Cycle Status Report >>Date: Wed, 5 Nov 1997 15:06:17 -0500 >> >> >>Solar Cycle Status Report >> >>STATUS OF THE CURRENT SOLAR CYCLE: >> >> Everyone now agrees that we have finally observed the birth of >>solar >>cycle 23. We have probably been immersed within this new cycle for some >>time. According to sunspots, the minimum occurred in May 1996 with an >>as yet >>unofficial smoothed sunspot number of 8.1. Since then, we have observed >>a >>steady increase in the number of new-cycle sunspots having the proper >>new-cycle magnetic polarities. At the time of this writing, most of the >>new >>sunspots which are appearing are new-cycle spots. >> >> >> According to the number of days in which no sunspots appeared, the >>cycle >>minimum (or maximum number of spotless days) occurred in October 1996 >>when >>there were 26 spotless days. This month also corresponds with the >>lowest >>monthly observed sunspot number of 2.3 (reported by SEC) and 1.8 >>(according >>to the International Relative Sunspot Number [RI]). >> >> >> In addition, butterfly plots showing the emergence of new solar >>sunspot >>regions according to solar latitude indicates a clear separation in >>formation >>latitudes from old cycle 22 and new cycle 23. There are also many other >>parameters which have shown that new cycle 23 is now firmly in-progress. >> >> >> This conclusion is a mixed-blessing for industry. >> >> >> Radio communicators can now begin to look forward to an >>increasinglyproductive reign of ionospheric radio communications. In >>fact, higher-band >>high-frequency (HF) radio communications are already beginning to be >>observed. By July of 1998 (within the next 12 months), the observed >>sunspot >>number should almost triple in magnitude from a current predicted >>smoothed >>value of 40 for June 1997 (predicted through regression methods) to 109 >>(plus >>or minus 25) by July 1998. This will substantially increase the >>strength of >>the ionosphere. The next year will therefore be an exciting one for >>radio >>communicators. >> >> >> The predicted smoothed sunspot number over the next 9 years is >>predicted to follow this pattern: >> >> >> Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec >>1997 019 022 027 030 034 040 044 050 054 060 066 071 >>1998 077 082 088 093 099 103 109 113 119 123 128 131 >>1999 136 139 142 146 148 151 153 154 156 157 158 159 >>2000 160 160 160 160 159 158 157 156 155 154 152 150 >>2001 148 146 142 140 137 134 131 128 124 121 118 114 >>2002 111 107 103 100 097 093 089 086 082 079 076 072 >>2003 069 066 062 060 057 053 051 048 046 043 041 039 >>2004 036 034 032 030 028 027 024 023 021 020 019 017 >>2005 016 014 013 012 012 011 010 009 009 008 *** *** >> >> >> The predicted smoothed 10.7 cm solar radio flux values over the >>next 9 >>years is predicted to follow this pattern: >> >> >> Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec >>1997 077 080 084 087 091 096 100 105 109 114 119 124 >>1998 129 134 139 144 149 153 158 162 167 171 175 178 >>1999 182 185 188 191 193 196 198 199 201 202 203 204 >>2000 205 205 205 205 204 203 202 201 200 199 197 195 >>2001 193 191 188 186 183 181 178 175 172 169 166 163 >>2002 160 156 153 150 147 144 140 137 134 131 128 125 >>2003 122 119 116 114 111 108 106 103 101 099 097 095 >>2004 092 091 089 087 085 084 082 081 079 078 077 075 >>2005 074 073 072 071 071 070 069 068 068 067 *** *** >> >> >> Satellite operators and users of satellite technology are less >>impressed >>with the onset of this new cycle of activity. The increased number of >>sunspots implies an attendant increase in the number of solar flares >>capable >>of spewing out particles that can charge and damage sensitive electronic >>components. The number of associated Earth-directed coronal mass >>ejections >>will also increase. This all means that users and owners of satellite >>technology will have to be increasingly aware of potential Earth-bound >>interplanetary disturbances. The death of the Telstar 401 satellite has >>beenunofficially attributed to the arrival of such a disturbance, >>combined with >>the effects of higher-than-normal densities of energetically charged >>electrons. That particular interplanetary disturbance was about the >>size of >>a mouse when you think of what is yet to come over the next 4 to 6 >>years. >>The largest interplanetary disturbances which we will observe during >>solar >>cycle 23 may be closer in size to an elephant than the small mouse we >>observed that may have contributed to the sudden death of Telstar 401. >>The >>overwhelming message which should be sent to users of satellite >>technology >>during this new solar cycle is "be cautious." >> >> >> Electrical hydro operators have enjoyed several years of quiet >>conditions. Nothing similar in magnitude to the events of March 1989 >>have >>been observed, where almost the entire electrical grid of electricity >>supplied to the province of Quebec collapsed within less than 2 minutes >>due >>to powerful electrical currents that were induced into Hydro Quebecs >>electrical power lines during one of the strongest geomagnetic storms on >>record. Since most of the electrical power lines and companies >>interconnect >>their lines, this outage had impacts all across North America. The >>additional load drawn from other power companies to compensate for the >>loss >>observed during the Quebec blackout brought many other power companies >>close >>to similar failure conditions. If the situation was slightly worse, >>other >>blackouts across North America could have been observed - possibly >>making >>this a much larger continent-wide type of power blackout instead of a >>relatively localized province-wide Quebec blackout. >> >> >> Oak Ridge National Laboratory studied the effects that a >>geomagnetic >>storm might have on the U.S. economy if the storm was only slightly >>larger >>than the one observed in March 1989. Their estimate of the impact of >>such a >>disturbance to the Gross Domestic Product alone put total economic costs >>in >>the U.S. in the $3 to $6 BILLION dollar range! This assessment, along >>with >>reviews conducted by the North American Electric Reliability Council >>placed >>the 1989 and 1991 geomagnetic storm events in a category equivalent to >>hurricane Hugo and the San Fransisco earthquake in its relative impact >>to the >>reliability of the electric power grids in North America. That's a >>sobering >>thought for hydro operators and everyone reliant upon electricity! >> >> >> The ability to predict conditions condusive to such large storm >>events >>will receive a considerable boost later this year when NASA's ACE >>satellite >>(Advanced Composition Explorer) is due to be launched. This satellite >>will >>provide near-continuous sampling of the space environment upstream of >>the >>Earth. It will provide as much as about 60 minutes of lead-time to the >>arrival of disturbances at the Earth. This should be sufficient time to >>allow hydro operators to prepare and watch for the damaging conditions >>that can follow interplanetary disturbances. >> >> >> Predictions of geomagnetic activity show that the number of minor, >>major >>and severe geomagnetic storms will steadily increase. The year with the >>maximum number of minor storm days is expected in the year 2005 during >>the >>decline of solar cycle 23 when the occurrence frequency of geoeffective >>coronal holes will reach a maximum. Over 40 minor storm days are >>expected in >>the year 2005. During the solar maximum year of 2000, coronal mass >>ejection >>induced minor storms should number at about 30 during the year. This is >>more >>than double the number of minor storm days expected during 1997. Major >>geomagnetic storming is expected to peak in the years between 1999 and >>2002. >>Severe geomagnetic storming, which is very difficult to predict, should >>peak >>in frequency between the years 1999 and 2005 with the preferred year of >>peak >>severe storm frequency being 2002. >> >> >> People interested in observing aurora's will be happy to know that >>we >>are well on our way to seeing larger events. Over the next 3 to 6 >>years, we >>will see many very significant auroral displays that should cover much >>of the >>U.S. and all of Canada. Activity observed during the last 3 years has >>been >>very miniscule compared to the events we can expect to observe during >>this >>new cycle. The largest of these events should be sufficiently intense >>to >>produce visible auroral activity from as far south as Florida! Although >>this >>is horrendous news for satellite users, radio communicators, navigators, >>surveyors and others, it is exciting news for those who love to watch >>for >>these awesomely powerful atmospheric displays of activity. >> >> >> The frequency and magnitude of solar flares is also expected to >>increase >>considerably over the next 3 to 6 years. Over the last few years, most >>of >>the solar flares we have observed have been very small and >>insignificant. As >>we approach the new millenium, the influence and power output of solar >>flares >>could increase by several orders of magnitude. The largest solar flares >>of >>this new solar cycle will almost certainly be at least 10,000 times more >>powerful than the majority of smaller flares we have observed over the >>last >>couple of years. These rogue flares could begin to be observed as early >>as >>1998 with a peak expected in the years between 1999 and 2003. >> >> >> Broken down, the number of M-class flares observed during an entire >>year >>should follow a pattern similar to this: >> >> >>1997 1998 1999 2000 2001 2002 2003 >>2004 >> 15 40 220 530 370 540 >> >> >> The number of X-class flares observed during an entire year should >>behave similar to this: >> >> >>1997 1998 1999 2000 2001 2002 2003 >>2004 >> 1 5 15 40 30 50 >> >> >> >> Major proton flare events capable of increasing proton densities in >>the >>near-Earth space environment are expected to reach a maximum between the >>years 1999 and 2003 with a double-maximum predicted for the years 2000 >>and >>2002. The number of predicted solar proton events is expected to >>increase >>slightly in 1998 and then more than triple between 1998 and 1999. There >>could be a fairly copious number of solar proton events during cycle 23. >>Estimates range from about 8 to as high as about 16 per year during the >>years >>of maximum proton flaring. >> >> >> These are just a few of the events we can expect to observe during >>this >>new solar cycle. >> >> >> The new millenium should be ushered in a BANG! Periods of solar >>activity will be observed that will be capable of literally shaking >>space! >> >> >>Everything from current solar and geophysical indices to >> current auroral activity sighting reports, daily reports, alerts and >> warnings, and much more can now be found at: >>http://solar.uleth.ca/solar >> >> >> >> > > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "David A. Nelson" Subject: latest addition Date: Fri, 07 Nov 1997 19:13:33 +1200 greetings all, on behalf of the group I extend a warm welcome to Francesco Nucera, he is from central Italy not too far from all that activity a few weeks ago. he is also the 3rd Itilian station on the map and in the database. BTW some very good looking seismograms from you guys from the Calif./Nev. events etc. chow 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: "David A. Nelson" Subject: monster event Date: Sun, 09 Nov 1997 00:40:39 +1200 tibet region of China 97/11/08 10:02:48 35.04N 87.31E 10.0 7.9Ms A XIZANG Dace 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: LARGE EVENT 7800 km from Italy Date: Sat, 08 Nov 1997 18:54:59 +0100 My station have registered a large event today at 10.12,25 GMT The preliminar location show an event about =7 Mb 7800 E from Italy, (India - China border region) Confermed by USGS **************************************************************************** ******************** FRANCESCO NUCERA Osimo - Ancona - ITALY Lat. 43.48N Long. 13.48E donjuan@........... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: watson@................ (Charles Watson) Subject: faults in the northern Xizang? Date: Sat, 08 Nov 1997 11:01:22 -0700 My maps do not show the faults in the northern Xizang Province. I have the Altyo Tagh along the Kulan Shan but today's Mw 7.6 quake seems to be some distance to the south. The Harvard CMT focal mechanism suggests strike-slip movement along an east-west direction. They also suggest the quake was shallow >> surface ruptures are likely. Anyone have an idea what fault system today's quake may have been on? -- ---/---- 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: Francesco Subject: Re: faults in the northern Xizang? Date: Sat, 08 Nov 1997 21:56:38 +0100 Hello Charles, could you beep me a good mapit program, w95 compatible, for isolate the events easily, knowing latitude and longitude? (even to download on the web) Thank you very much Francesco Nucera Osimo - Ancona Italy At 11.01 08/11/97 -0700, you wrote: >My maps do not show the faults in the northern Xizang Province. I have >the Altyo Tagh along the Kulan Shan but today's Mw 7.6 quake seems to be >some distance to the south. The Harvard CMT focal mechanism suggests >strike-slip movement along an east-west direction. They also suggest the >quake was shallow >> surface ruptures are likely. > >Anyone have an idea what fault system today's quake may have been on? > > >-- >---/---- >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) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: lahr@................. (Dr. John Lahr (USGS-GI Seismologist)) Subject: XIZANG Mw 7.4 - 7.6 earthquake Date: Sat, 8 Nov 1997 14:42:26 -0900 > From condor@................ Sat Nov 8 03:14:08 1997 > From: condor@................ > Date: Sat, 08 Nov 1997 05:16:52 MST > To: lahr@................. > Subject: From KOYANAGI via USGS EasyNet > > > Message processed by EasyNet 08 Nov 1997 at 12:16 UTC: > > From: NEIS::KOYANAGI "Stuart Koyanagi" 8-NOV-1997 05:15:41.00 > To: CONDOR > CC: > Subj: EQ MAG 7.9 XIZANG > > U.S. GEOLOGICAL SURVEY NATIONAL EARTHQUAKE INFORMATION CENTER > World Data Center A for Seismology > > Reply to: sedas@................ (internet) > sedas@................. (internet - alternate) > ISDMNL::NEIS::SEDAS (SPAN) > > The following is a release by the United States Geological Survey, > National Earthquake Information Center: A major earthquake occurred > IN XIZANG about 430 miles (700 km) north-northwest of Lhasa or about > 520 miles (840 km) north-northeast of Kathmandu, Nepal at 3:03 AM > MST today, Nov 8, 1997 (6:03 PM local time in Xizang). A > PRELIMINARY MAGNITUDE OF 7.9 WAS COMPUTED FOR THIS EARTHQUAKE. The > magnitude and location may change slightly as additional data are > received from other seismograph stations. No reports of damage or > casualties have been received at this time; however, this earthquake > may have caused damage due to its size. This earthquake is believed > to be the largest instrumentally recorded event in this area to > date. > > >Date: Sat, 8 Nov 1997 14:12:42 -0700 (MST) > >From: Stuart Sipkin > > 97/11/08 10:02:48.81 > XIZANG > Epicenter: 35.044 87.310 > mb 6.1 MS 7.9 > > MOMENT TENSOR SOLUTION > Depth 29 No. of sta: 20 > Moment Tensor; Scale 10**20 Nm > Mrr= 0.16 Mtt=-1.04 > Mff= 0.88 Mrt= 0.09 > Mrf= 0.02 Mtf= 1.19 > Principal axes: > T Val= 1.45 Plg= 3 Azm=296 > N 0.16 86 75 > P -1.61 2 206 > > Best Double Couple:Mo=1.5*10**20 > Mw=7.4 > NP1:Strike=341 Dip=86 Slip= 180 > NP2: 71 90 4 > > > ------- > ###-------------- > ######--------------- > #########---------------- > ###########----------------- > T ############----------------- > ############----------------- > ################-----------###### > #################-----########### > ################################# > ###########-------############### > ######------------############### > ------------------############# > -------------------############ > ------------------########### > -----------------######## > -- ----------###### > P -----------### > ------- > > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: Alabama 10/24/97 Date: Wed, 12 Nov 1997 18:26:16 -0700 Charlie Rond and the PSN- That is a very nice record of the Atmore, Alabama, Earthquake. I have just returned to the office after leaving somewhat unexpectedly for Alabama on Monday 27 Oct to assist in a USGS aftershock investigation of the earthquake. I had intended to email the PSN-L from the field, but I encountered some connectivity problems and wasn't online from the motel until just before we left on Saturday 1 Nov. Following the field study, I spent a week at a Buddhist meditation retreat that I had scheduled prior to the earthquake: just an attempt to deal with my internal signal/noise problems. I plan to put some of the Alabama aftershock records we recorded with portable seismographs on a USGS website in the near-future. In the meantime, I am forwarding an email from Joan Gomberg, USGS/CERI at the University of Memphis, who coordinated field activities that summarizes the earthquake investigation. -Edward PS. It has taken me almost two days to go through the mostly PSN-L email of the past two weeks. Charlie Rond wrote: > > Larry, > > Here is a late delivery on the Alabama 4.9 event. I'm having to learn > how to upload these to your page. > > --Charlie Rond > > --------------------------------------------------------------- > > Name: 971024A.RM1 > Part 1.2 Type: unspecified type (application/octet-stream) > Encoding: base64 > > --------------------------------------------------------------- > > 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 -- 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: Edward Cranswick Subject: [Fwd: seismographic quotation and info] Date: Wed, 12 Nov 1997 18:54:27 -0700 -- 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". Hi ! Please send aproximate price references of low end seismographic equipment. We are an astronomical observatory, where hi precission instrumentes (telescopes) are pointing to the sky with arc-second accuracy. The telescopes are normally "pointed" to an object based on theoretical or mapped coordinates, which are corrected for instrumental errors (telescope mechanical optical flexure) with apropiate ponting-software model, which has several degree parameter inputs. The pointing is in general quite satisfactory, however sometimes we detect some (small) "jumps" which are not readily explained. We believe it coud be seismic activity (?). In order to prove (or not) we need some seismographic instrumentation which gives enough data for our pourposes, which is probably much less demanding than the normal commercial or scientific applications. We are on a tight budget, so we are looking for some simple solution. We think that a common accelerometer with some hi sensitivity low-pass amplifier hooked to a PC may probably do, but have no experience.... Your comments and suggestions are most WELCOME !!! Thank you !! :-) Gero *--------1---------2---------3---------4---------5---------6----- * Gero Timmermann gtimmerm@....... home: (56-2) 273-4348 * http://www.eso.org/~gtimmerm CUSeeMe: 134.171.81.90 * European Southern Observatory, ESO LaSilla, Mangmt,Tech.Supp. * POBox 19001, Santiago-19, CHILE - Phone: (56-2) 207-3397 x4456 *********1*********2*********3*********4*********5*********6 From: Edward Cranswick Subject: [Fwd: ] Alabama Earthquake Date: Wed, 12 Nov 1997 18:58:17 -0700 -- 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". Friends of the 10/24/97 Alabama Earthquake... Here is an abbreviated report on our field experience and a rough list of things that I think need to get done to put together a complete story about this earthquake sequence (am sure it's by no means complete). I'm willing and interested in trying to coordinate all these activities (would also be happy to share this responsibility with someone), and certainly hoping that y'all (my 'southern' really improved last week) will be interested in participating by volunteering to do some piece of the study. Please let me know if I've forgotten something, or someone who might also be interested in participating in this, or if you're not interested. As you see, there are lots of interesting pieces, and opportunities for good collaborative work and publications. Last week's field activities included deployment of a now 11 station seismic network (Tom Bice, David Carver, Edward Cranswick, Lorraine Wolf, and myself), collection of intensity information (Dorothy Raymond), preliminary examination of available data from the Alabama State Oil and Gas Board (Dorothy Raymond, Richard Raymond, Lorraine Wolf, and myself). Assistance was also provided by the Escambia County Emergency Management Agency, and lots of local citizenry. There were two felt aftershocks and at least three smaller ones evident in preliminary examination of the seismic data recorded. Seismographs were operated in continuous recording mode for two to five days and are all still in the field running in triggered mode. Two MEQs were also operated for ~five days. The intensity information seems to be quite consistent with preliminary instrumental locations. There may be one example of ground failure (?), although it is quite subtle, if real. The State Oil and Gas Board is willing to provide any of their records, which include monthly logs of well head pressures, volumes of fluids injected or withdrawn, etc. The epicentral region is quite close (within a few km) to one of the smaller fields and within ~10 km from the largest fields. Both passive production and injection (forgive use of inappropriate terms!) are done, and well depths range from 5000' to 15000'. The primary fault system runs within a few km of the epicentral region. The following is my 'to do' list organized loosely by topic. Seismology Examine closest permanent station data (CERI's Pickwick station, Tim Long's?) for evidence of prior activity in the same area. Determine focal mechanisms from regional data (Bob Hermann and Chuck Ammon have already begun this). Prepare portable seismographic data for analysis Compile all field notes Organize data recorded to date in PASSCAL database Compile site information (for ground motion studies) Identify all events, produce catalog (locations, magnitudes, focal mechanisms?) Prepare SEED volume for IRIS DMC Service/recover field instrumentation Cluster test to verify responses, polarities? Oil and Gas Data Compilation & Analysis Contact expert from USGS Energy Team? Determine relevant information to compile. Computerize (logged information is available in printed format). Correlate with seismologic and geologic information. Intensity Compile data for all felt events from newspaper and post-office solicitations. Determine mainshock isoseismal limits - to constrain depth and attenuation, possible directivity? Compare mainshock and aftershock intensity patterns, intensity and instrumental info. Find out if oil or gas pipelines were damaged. Misc. Search newspapers for previous reports of earthquakes in the region. Determine if there's any geodetic information from the region. GIS? Mapping Prepare a base map with geology, geography (Susan Rhea has already started a GIS map?). Add seismic station locations, instrumentally determined information. Prepare layer with intensity information. Prepare layer with production field information. Joan Gomberg US Geological Survey c/o The University of Memphis Campus Box 526590 Memphis, TN 38152-6590 (901) 678-4858 (901) 678-4897 (FAX) From: Edward Cranswick Subject: Re: seismographic quotation and info Date: Wed, 12 Nov 1997 19:15:40 -0700 Gero- You could buy a commercial seismograph for $10k-$20k or use a PC in conjunction with a some other hardware/software costing about $1k. I have forwarded your email to the Public Seismic Network listserver and you should receive some suggestions from them. Since you observe "jumps" which would seem to be displacements of the pointing direction, perhaps it would be more useful to record velocities rather than accelerations. For the first step, I suppose the most important matter is to determine whether there is any temporal correlation between the "jumps" and independently recorded seismic events. Do you have a way of precisely recording the time of the "jumps". -Edward Gero Timmermann wrote: > > Hi ! > > Please send aproximate price references of low end seismographic > equipment. > > We are an astronomical observatory, where hi precission > instrumentes (telescopes) are pointing to the sky with > arc-second accuracy. > The telescopes are normally "pointed" to an object based on > theoretical or mapped coordinates, which are corrected for > instrumental errors > (telescope mechanical optical flexure) with apropiate > ponting-software model, > which has several degree parameter inputs. > The pointing is in general quite satisfactory, however sometimes > we detect some (small) "jumps" which are not readily explained. > We believe it coud be seismic activity (?). > In order to prove (or not) we need some seismographic > instrumentation which gives enough data for our pourposes, which > is probably much less > demanding than the normal commercial or scientific > applications. We are on a > tight budget, so we are looking for some simple solution. > > We think that a common accelerometer with some hi sensitivity > low-pass amplifier hooked to a PC may probably do, but have no > experience.... > > Your comments and suggestions are most WELCOME !!! > > Thank you !! :-) > Gero > > *--------1---------2---------3---------4---------5---------6----- > > * Gero Timmermann gtimmerm@....... home: (56-2) 273-4348 > > * http://www.eso.org/~gtimmerm CUSeeMe: 134.171.81.90 > * European Southern Observatory, ESO LaSilla, Mangmt,Tech.Supp. > > * POBox 19001, Santiago-19, CHILE - Phone: (56-2) 207-3397 x4456 > > *********1*********2*********3*********4*********5*********6 -- 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: Iceequeen@....... (by way of Larry Cochrane ) Subject: Telemetry Date: Wed, 12 Nov 1997 22:08:06 -0700 Hi Everyone, I received this from Katie the other day. If you have any info for her please send it directly to her since she is not on the list. KATIE UNDERWOOD 17 HIGHLAND MEADOWS DRIVE JACKSON, MISSISSIPPI 39211 (601) 362-1355 ICEEQUEEN@....... Dear Mr. Cochrane: I am a junior at Saint Andrew's Episcopal School in Ridgeland, Mississippi. For the past two years, I have been conducting extensive independent research in the field of engineering, specifically designing seismographs. Consequently, I have become involved in science fairs and science competitons. Last year I built a modified version of the James D. Lehman seismograph, with plans downloaded from the PSN website, as well as one of your amplifer boards. The modified Lehman proved very successful, graphing earthquakes around the country, including the Clakre County, MS earthquake March 25, 1996--the only seismograph in the state to record it. Do to a successful year in state science fair competitions, I was selected to represent Mississippi in the 47th International Science and Engineering Fair held in Tucson, AZ. This year I designed a portable seismograph using three accelerometer sensors, which are positioned to measure x, y, and z axes. The seismograph is unique in that it does not have to be balanced and is rugged enough to be thrown or possibly launched from almost any location and still accurately record both motions and vibrations. I have hypothesized that this device will not be sensitive enough to record long-distance earthquakes, and my current observations confirm this. However, I do believe that it can be used for many applications beyond seismic research. Due to its ability to measure and record the intensity and direction of vibrations and other disturbances, I have hypothesized that its outputs could be fed to a modified flight recorder "black box." I believe that this information could be used to analyze and determine the cause of many in-flight anomalies, such as strength, direction, and perhaps the location of unusual vibrations, accelerations, or other movements. If the hypothesis proves correct, this analytical ability could prove valuable in determining the cause of various mechanical and structural failures, and might assist in predicting and avoiding some of these same problems. This spring I was selected to represent Mississippi again in the 48th Intel International Science and Engineering Fair held in Louisville, Kentucky. At the fair, I received a first place award from the Society of Exploration Geophysicists, a second place award from the United States Department of the Interior, Bureau of Reclamation, as well as Third Place Grand Award in the Engineering Category from Intel. I am interested in conducting experiments with my portable seismograph using accelerometer chips. It would be most convenient if I had an A-D converter that would plug into my notebook computer PCMCIA slot. I have noticed that Jameco has a PCIA-7IB card avaliable. Do you have any experience with this model, or could you make any recommendations for a PCMCIA card compatible with the SDR software? I am also interested in the Telemetry Demodulator Board advertised of the PSN website, but I was unable to upload any further descriptions or cost information of the device. I would like to construct a telemetry link between my portable sensor and a receiver to be located at my notebook computer. Any information of ideas you have would be gratefully appreciated. Sincerely, Katie Underwood _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David Josephson Subject: Re: Telemetry Date: Thu, 13 Nov 1997 00:39:10 -0800 (PST) Hello Katie, Good to see that there is *someone* young doing independent science and technology research! My thing was radio (broadcasting, propagation, and audio) and after playing with corporate America for 12 years I started my own company making new and different kinds of microphones. Unless it's changed a lot, school will not be aligned with your sort of independent work, but if you play it right you can take what you can use and keep your own ideas intact. Using a three-axis array of solid state or piezoelectric accelerometers is a good way to record any sort of vibration or shock signature. But as you know more sensitivity is needed for earth seismic use. Your idea about using it in aircraft is good -- but old! During flight test, aircraft are heavily instrumented with accelerometers to monitor vibration of critical surfac