Small quake rattles Calif.'s East Bay

OAKLAND, Calif., Sept. 6 (UPI) -- A small earthquake rattled San Francisco's East Bay area Friday night, causing no apparent damage, seismologists said.

The magnitude 4.0 temblor was centered near Alamo, Calif., about 10 miles underground, and was felt in Contra Costa and Alameda counties, the San Francisco Chronicle reported.

David Oppenheimer, a seismologist with the U.S. Geological Survey, told the newspaper the quake happened in an unnamed fault more than two miles from the larger Calaveras fault. The last time a quake was centered there was in 1990, when a cluster of quakes caused minor structural damage to some homes, he said.