>Mary:
I'm not familiar with the Big Bear Lake quake. However, it sounds
like an aftershock. The mechanism for aftershocks is that after a
fault slips, the stress is transferred to other parts of the fault.
These parts then slip, too, although usually the amount of slip is
much less than the original fault. There can be many aftershocks. P
waves radiate from an earthquake and pass at the speed of sound. The
earth (the WHOLE earth) sometimes will 'ring' after a big earthquake,
i.e., it'll quiver a bit. Imagine suspending a steel sphere from a
string. If you hit the sphere, it'll ring for a bit - that's the
earth after a big earthquake. But this ringing is detectible only
with the most sensitive equipment and it will NOT trigger other
earthquakes. Also, on the fault zone there is occasionally evidence
of melt production. But, this usually takes place at great depth and
only over small patches (square meters). I doubt this had much to do
with the Big Bear Lake earthquake.
If you can tell me where the Big Bear quake was (distance from
Landers) I can probably tell you more.
DVW
>Hi
>I'm a student of geology and I have questions relating to p waves. eg. when
>the Landers quake triggered the Big Bear quake (taking approx. 3 hours to
>do so), wouldn't this have been due to the p waves? Or was it the change in
>the overall points of pressure that triggered it?
>
>Can p waves do this? And, if so, would it be because the ions which make up
>the basic structure of the rock are given a boost of energy from the p
>wave? Perhaps giving them the ability, for a time, to be as the mantle -
>solid but liquid like.
>
>Just wondering if anyone knew.
>Mary
+===========================================================+
Dave Wiltschko
Dept. of Geology and Geophysics
and Center for Tectonophysics
Texas A&M University
College Station, TX 77843-3115
Voice: 409 845 9680
Fax: 409 845 6162 or 409 845 3002
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