## PSN-L Email List Message

Subject: How the earth moves
From: tchannel1@............
Date: Fri, 4 Jan 2008 07:08:29 -0700

```Happy New Year, Folks.

When I receive an earthquake, the earth and my house are moved by the =
event.  The various phases moves the ground in different direction.
This question has to do with the movement of the earth like that of a =
teeter-totter.  Tilt. like that measured by a level.

1.  How much does the earth move?  I do understand the earth would move =
in many different directions, and move more, if the earthquake was =
larger, and or closer.
But somewhere I think I read some numbers indicating how much the earth =
would be expected to move.

I am asking this question, to help me understand, the approximate tilt =
from an earthquake.   If I hung a one meter pendulum, and a major =
earthquake occurred 1000km away, the earth here, would tilt.  If I were =
looking at the pendulum at the moment the S wave arrived, assuming the =
sensor was pointing in the correct direction, the pendulum would appear =
to tilt, but unless the event was large enough I could not see it with =
my eyes.
If the event was large, I would be able to see it with my eyes.

I saw the earth move during an earthquake 1993?   I was at my kitchen =
window felt or hear something, maybe the P,looked up, and maybe 4 =
seconds later, I felt a wave, one up and one down.  As I was looking =
outside at the time I saw the wave move down the street.   If I believed =
my eyes.  This wave was not 12", but it must have been more than 2".

Anyhow I think you get the idea.

2. Completely different question:  I would like to correspond with =
someone who has used both AmaSeis and WinSDR.   I know AmaSeis, but =
would like to get some pointers on setting up WinSDR. =20

Happy New Year, Folks.

When I receive an earthquake, the earth =
and my=20
house are moved by the event.  The various phases moves the ground =
in=20
different direction.
This question has to do with the =
movement of the=20
earth like that of a teeter-totter.  Tilt. like that measured by a=20
level.

1.  How much does the earth =
move?  I do=20
understand the earth would move in many different directions, and move =
more, if=20
the earthquake was larger, and or closer.
But somewhere I think I read some =
numbers=20
indicating how much the earth would be expected to move.

I am asking this question, to help me =
understand,=20
the approximate tilt from an earthquake.   If I hung a one =
meter=20
pendulum, and a major earthquake occurred 1000km away, the earth here, =
would=20
tilt.  If I were looking at the pendulum at the moment the =
S wave=20
arrived, assuming the sensor was pointing in the correct direction, the =
pendulum=20
would appear to tilt, but unless the event was large enough I could not =
see it=20
with my eyes.
If the event was large, I would be able =
to see it=20
with my eyes.

I saw the earth move during an=20
earthquake 1993?   I was at my kitchen window felt or =
hear=20
something, maybe the P,looked up, and maybe 4 seconds later, I felt a =
wave, one=20
up and one down.  As I was looking outside at the time I saw the =
wave move=20
down the street.   If I believed my eyes.  This wave was =
not 12",=20
but it must have been more than 2".

Anyhow I think you get the =
idea.

2. Completely different question:  =
I would=20
like to correspond with someone who has used both AmaSeis and=20
WinSDR.   I know AmaSeis, but would like to get some pointers =
on=20
setting up WinSDR.

Thanks, Ted
```