"John Bartley I solved my XP problems w/ Service Pack Linux"
wrote in message
om...
This fellow, two decades ago, worked on a cheap radio monitoring
system which was studied by the USGS. He noted the study showed 70%
accuracy in finding when quakes were about to happen.

http://www.rexresearch.com/tate/tate.htm#radio

"In studying several smaller earthquakes from 1985-1987, it appeared that
the larger the earthquake, the larger and sooner the precursors appeared.
The 6.0 earthquake of April 24, 1984 was preceded by a radio depression 6
days before the shock. The Loma Prieta Earthquake of about 7.0 magnitude was
preceded by a much greater radio depression 60 days before. A 7.0 magnitude
quake is 10 times greater than a 6.0. The 60-day precursor time for the 7.0
earthquake was 10 times the precursor time for the 6.0 earthquake. More data
is needed to clarify this relationship."

He may really have something here, but, absent other evidence, how can you
prove correlations between events six days apart, much less 60? Further,
there is no indication of where the quakes will occur. Assuming signal
levels are depressed, it should be possible to monitor signal levels from
several regional broadcast stations from several locations, which might help
pinpoint the source of the absorption (assuming that's what it is). His
claimed accuracy of 70% is only significant if it is possible to designate
the area(s) in which tectonic events are pending. The seismic situation in
California would probably allow that much "accuracy" through random
predictions that an earthquake is about to occur.

The Schlumberger brothers pioneered modern oil-reservoir location in the
1930s by measuring ground resistance during controlled underground
explosions. I believe similar methods have been used to try to detect
earthquakes. The problem with this method is, you have to cover the ground
with closely spaced sensors. That's hard to do in the highly populated
earthquake zones of California.

"PM"