Bay Area vulnerable to large quake, scientists say

Bay Area vulnerable to large quake, scientists say

OAKLAND, Calif. (October 14, 1999 1:48 p.m. EDT http://www.nandotimes.com) - A federal study released Thursday shows there is a 70 percent chance that a large earthquake will strike the San Francisco Bay area in the next 30 years.

That's because there are a number of faults slicing through heavily developed areas around San Francisco, more chances they will rupture and more people who will be affected when they do, the study concluded.

The estimate from the U.S. Geological Survey is slightly greater than that found by a 1990 study because it spreads the earthquake hazard over a much broader region. It also lowers the bar for a large earthquake.

The study lowered the definition of a large earthquake to magnitude 6.7 to match the strength of the 1994 Northridge quake, which killed 57 people and caused $20 billion in damage in Southern California. The 1990 study had estimated a 67 percent chance of a magnitude 7.0 earthquake by 2020.

"The whole purpose of our research is to use science to contribute to safer communities," USGS geologist David Schwartz said. "Although we can't predict or prevent earthquakes, we can all prepare for them."