USC has moved one step forward to predicting the 'big one' in Los Angeles. They might not be able to say when, but they hope to say where and how hard.
The university announced Tuesday its testing a new earthquake forecasting method that aims to predict the approximate size and location of future quakes.
The computer-based model cannot predict the timing of a quake, but it may be the first to provide an indirect measure of the stress inside the earth, and therefore a reasonable estimate of the size and location of future quakes, according to Danijel Schorlemmer of the University of Southern California College of Letters, Arts and Sciences.
Local news from across Southern California
The third in a series of papers in the journal Nature explains the forecasting method. Schorlemmer is the senior author of the most recent paper, published online Thursday. He was the first author of two related papers in Nature, both published in 2005.
"One of the key aspects in forecasting of earthquakes is stresses," Schorlemmer said. "The findings in the three papers help identify locations that are highly stressed from readily available earthquake catalogs."
Seismologists believe that the buildup of stress deep in the earth causes earthquakes. Monitoring such stress has proven impossible to date.
While the timing of quakes remains unpredictable, the new model adds to the science of earthquake forecasting, Schorlemmer said.
"We are observing the little aftershocks all over California, deriving the state of stress and trying to predict the future main shocks," he said. "It's not perfect. It's the only proxy (for stress) we could come up with so far."
The model is now being tested by the Collaboratory for the Study of Earthquake Predictability, an international project started by Thomas Jordan, director of the Southern California Earthquake Center based at USC.
CSEP is testing several forecast models along with Schorlemmer's. Because the test needs to run at least five years, results are not yet available, university officials said.