California seismologists have discovered a new fault line running along the northeastern edge of the Salton Sea, parallel to the infamous San Andreas Fault. The findings were published last week in the “Bulletin of the Seismological Society of America” by seismologists from the University of California, San Diego and the University of Nevada, Reno.
New fault lines are rarely discovered. California, in particular, is very seismically active and has been extensively surveyed. The Salton Trough Fault, however, was undiscovered until now because it was underwater. “The location of the fault in the eastern Salton Sea has made imaging it difficult and there [are] no associated small seismic events, which is why the fault was not detected earlier,” said principal investigator Neal Driscoll, a geologist at the University of California, San Diego.
The study was published in the wake of nearly 200 mini earthquakes in the same area at the end of September. The confluence of quakes temporarily increased the risk of a major quake (magnitude 7 or higher) in the region to about 1 in 100. “Any time there is significant seismic activity in the vicinity of the San Andreas fault, we seismologists get nervous, because we recognize that the probability of having a large earthquake goes up,” said seismologist Thomas H. Jordan, the director of the Southern California Earthquake Center. The risk has now dropped back down.
Valerie Sahakian, a researcher with the U.S. Geological Survey and lead author of the study, said the Salton Trough Fault was not connected to these earthquakes.
Yet there is much the researchers still do not know about the newly-discovered fault. More research needs to be conducted to understand the fault’s full length and location. Once more information is known about the fault, scientists can then better assess the risk of
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