8.9 Magnitude Earthquake? Not On The San Andreas Fault

It is unlikely that California’s feared San Andreas fault could generate an earthquake of the magnitude that struck Japan and triggered a tsunami, a seismologist at the Scripps Institution of Oceanography said today.

The San Andreas is not deep enough to match the magnitude-8.9 quake that struck Japan, Dr. Debi Kilb said. But the fault could generate a magnitude- 8.4 temblor that would certainly be strongly felt in San Diego and elsewhere in Southern California, Kilb said.

Speaking hypothetically, a rupture running from south-to-north would deliver most of its energy toward Los Angeles, while a break in the opposite direction would expend its energy in Mexico, Kilb said.

“San Diego is sitting in a nice spot for a San Andreas earthquake,” Kilb said.

She said San Diegans would certainly feel such a shaker but would escape most of the damage that could impact other areas.

“It’s just a reminder we need to prepare for earthquakes,” Kilb said.

She said the one that struck Japan happened in an area where big earthquakes occasionally strike, including a magnitude-7.2 temblor on Wednesday.

The biggest of earthquakes from that region usually generate tsunamis, she said.

Seismologists are looking forward to studying the Japan earthquake to learn more about the composition of the interior of the earth and maybe answer questions about quake triggers, she said.