BERKELEY, Calif. (AP) – The San Francisco Bay area is likely to be hit by a major earthquake in the next 30 years, with the populous Interstate 880 corridor in the East Bay being particularly vulnerable to a catastrophe, according to a federal study released Tuesday.
The study found that the Bay Area had a 62 percent chance of being struck by a magnitude-6.7 or greater quake by 2032. That’s down from the 70 percent chance researchers estimated in 1999.
But that apparent decrease shouldn’t set residents at ease, researchers cautioned.
“Regardless of where earthquakes occur in the Bay Area, they will produce damaging ground motions over broad areas and at substantial distances from the source,” said David Schwartz, a government geologist.
The study was commissioned by the United States Geological Survey and conducted by the Working Group on California Earthquake Probabilities, a group of about 100 federal, state and academic researchers.
The most potentially hazardous of the region’s seven major faults is the combined Hayward-Rodgers Creek system, according to the study. The Hayward fault roughly parallels the densely populated Interstate 880 corridor, while the Rodgers Creek fault extends north of San Francisco into the city of Santa Rosa.
Only two faults – the San Andreas, which bisects the Peninsula, and the San Gregorio, which runs along the Pacific shore – were cited as large enough to produce a truly devastating quake of magnitude 7.5 or greater.
Researchers said that meant the Bay Area had only a ten percent chance of being struck by a quake of that size. On the other hand, the study suggested the region has an 80 percent chance being hit by at least one quake of magnitude 6.0 or greater.