[winoneforthegipper]

Soundwaves you say?.....lol

This is part and parcel to a quakes stress shadow research that I am a fan of..

However this one directly goes to what Cajun has been thinking, perhaps you can use their research as a starting point!

http://www.sciencedaily.com/releases/2008/01/080103124649.htm

[winoneforthegipper]

Here is the PDF for the position paper...

http://www.lanl.gov/orgs/ees/ees11/geophysics/nonlinear/2012/JohnsonJGR12Slow.pdf

[machogirl]

Good read. Thanks for the ping!

[machogirl]

Still looking for that paper I read about the “locked” area of the San Andreas south of Parkfield to San Bernadino producing waves that resemble harmonic tremors.

It was from the 2004 installation of the Parkfield Experiment Data. (IIRC)

[The Cajun]

Thanks for the info and interesting.
What I'm kind of looking for along those lines, is a complete spectrum analysis of the sounds (Booms or buzzing) that are sometimes heard, but so far not explained.
Sometimes a light display (flashes or apparent plasma spheres) are seen also.
They are sometimes called earthquake lights.
Just trying to connect some dots and tie things together.
Basically what is the fundamental frequency of the sound (where the most energy (amplitude) is seen), the harmonics and subharmonics of that frequency and their possible effects which may be different than what the fundamental frequency produces.
Just another thought, the audible sound heard may not be the fundamental frequency, it could possibly be a harmonic or subharmonic.
Doesn't happen all the time so I suspect several things have to occur just right for the phenomena to be heard or observed.
Another thing about the sound, by people hearing it, it seems to be directionless.
Just guessing there is an acoustic and electrical tie in to what is sometimes observed.
There has to be a lot of energy involved due to the loudness and area covered by the *booms/buzzing* and sometimes light flashes (lightening like, sheet and ball).
My question is, what is the primary source from underground that generates what is observed above ground.
Is it acoustic, electrical, mechanical or a combination of all?
Does it tie in occasionally to surface quakes?
I know the above is confusing as heck, but I think it's half way straight in my mind :)