Posted on 12/10/2004 8:59:17 AM PST by NYer
Mysterious tremors deep beneath the San Andreas Fault near the quake-prone town of Parkfield are shaking the earth's brittle crust, far below the region where earthquakes normally strike -- and scientists say they can't understand what's happening or what the motions mean.
Seismic researchers are monitoring the strange vibrations closely. But whether the faint underground tremors -- termed "chatter" by some seismologists -- portend an increased likelihood of a major quake in the area is an unsolved puzzle.
Robert Nadeau, a geophysicist at the UC Berkeley Seismological Laboratory, charted more than 110 of the faint vibrations since they were first detected by the lab's High Resolution Seismic Network in Parkfield three years ago. What concerns Nadeau and his colleagues is that the epicenter of the great 1857 Fort Tejon earthquake, whose magnitude has been estimated at 7.8 to 8, was located almost exactly where the deep tremors are now occurring -- beneath the San Luis Obispo County village of Cholame, some 17 miles south of Parkfield.
The episodes of chatter last from four to 20 minutes and are being recorded from as deep as 40 miles beneath the surface -- up to four times the depth of normal earthquakes, which originate in what scientists call the "seismogenic zone." That zone reaches no deeper than 9 or 10 miles below the Earth's surface.
(Excerpt) Read more at sfgate.com ...
No thanks. I'll stay and take my chances.
Back when this happened, there was an investigation as to whether the steam injection into the rock could have caused a collapse.
I wouldn't rule out some subsidence, but you'd basically have to dissolve solid rock and create an actual cavern, in order to cause a collapse.
A whole lotta shakin' goin' on!!
8 | the epicenter of the great 1857 Fort Tejon earthquake...was located...beneath the San Luis Obispo County village of Cholame, some 17 miles south of Parkfield. |
A measure of how devistating the 1857 Fort Tejon earthquake was, is the fact that the quake was named for Fort Tejon which is located some 120 miles distant (southeast) of the epicenter at Cholame. Destruction was recorded as far north as Sacramento and as far south as San Diego.
--Boot Hill
Hmmm....a correlation to fault lines and lefty commies in California?
No, lol
We are camping in the Rio Grande Valley, and we think the only natural phenomena we need worry about is some wind and rain storms. *crossing fingers and knocking on wood*
Ping to post #77...
with reference to past article "Satellites reveal a mystery of large change in earth's gravity field":
http://www.eurekalert.org/pub_releases/2002-08/nsfc-sra080102.php
LOL!!
FRegards,
Oh, great, my husband is working about 20 miles from Parkfield. And last time I was up there, we drove over and checked out Parkfield, spooky place.
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