January 24, 2009

Scientists See California Quake Pattern

Southern California could be overdue for a major earthquake along the San Andreas Fault, researchers say.

A study by scientists at the University of California at Irvine found there were five major temblors along a southern section of the San Andreas Fault in the past 700 years, the Los Angeles Times reported Saturday. The first one is estimated to have occurred in 1310, followed 83 years later by one in 1393, 192 years after that in 1585, the next 85 years later in 1640 and the last one 217 years later.

It's now been 152 years since the last major quake along the Carrizo Plain section of the San Andreas -- the Fort Tejon temblor of 1857, which was an estimated magnitude of 7.9.

Lisa Grant Ludwig, a principal investigator for the University of California-Irvine study, said scientists can't be sure that the pattern will hold.

But we know it increases the probability of an earthquake, she said. There's not any way I can look at the data and be comforted by it.

On Saturday morning, there was a 3.1 magnitude quake in central California, about 15 miles from Trona, Calif., the U.S. Geological Survey said.