## PSN-L Email List Message

From: "tchannel" tchannel@..............
Date: Tue, 9 Jan 2007 18:50:13 -0700

```Hi Folks,  These questions may have to do with art and experience, as =
much as science.  Can one explain how to read a Seismogram, if that is =
the correct word?  That is the enlarged section of the recorded trace.  =
I normally can find the P and S. I also understand the different =
directional movements, as illustrated in pictures I have seen.=20

1.  Are the large waves that follow the S, surface waves?
2.  If so can one discern Loves from Rayleigh's, within that section?
3.  Do the Loves and Rayleigh's arrive at different times, as with P and =
S? and or, do the look different?

I am sure the more you work with these recordings the better you can =
interpret them.

A related question:  I just recorded a very nice image of the 5.7m =
01/09/2007 Southeastern Alaska 2259km from Boise Idaho, using my =
Vertical Spring sensor.  The best recording, so far,  using this new =
sensor.   I was please with the image; a clear P, a smaller but clear S, =
followed by a large series of waves, I assume,  to be surface waves. But =
here I can't tell a Love from a Rayleigh.  =20
I did not know a vertical spring sensor would pick up surface waves, =
even though the Rayleigh's could move the vertical spring.  Is it that =
the vertical is less likely to pick up these waves at greater distances, =
because of their longer periods?

Thanks, Ted

Hi Folks,  These questions may =
have to do with=20
art and experience, as much as science.  Can one explain how to =
Seismogram, if that is the correct word?  That is the enlarged =
section of=20
the recorded trace.  I normally can find the P and S. I also =
understand=20
the different directional movements, as illustrated in pictures I =
have=20
seen.

1.  Are the large waves that =
S, surface waves?
2.  If so can one discern Loves =
from=20
Rayleigh's, within that section?
3.  Do the Loves and Rayleigh's =
arrive at=20
different times, as with P and S? and or, do the look=20
different?

I am sure the more you work with these =
recordings=20
the better you can interpret them.

A related question:  I just =
recorded a very=20
nice image of the 5.7m 01/09/2007 Southeastern Alaska 2259km from Boise =
Idaho,=20
using my Vertical Spring sensor.  The best recording, so far,  =
using=20
this new sensor.   I was please with the image; a clear P, a =
smaller=20
but clear S, followed by a large series of waves, I assume,  to be =
surface=20
waves. But here I can't tell a Love from a Rayleigh.   =

I did not know a vertical spring sensor =
would pick=20
up surface waves, even though the Rayleigh's could move the=20
vertical spring.  Is it that the vertical is less likely to =
pick up=20
these waves at greater distances, because of their longer =
periods?

Thanks, Ted

```