4.7 Quake Near San Jose Causes Light Damage and No Injuries

A magnitude 4.7 earthquake centered on an active segment of the Calaveras fault 10 miles east of San Jose was felt as a jolt or rolling motion throughout the Bay Area on Tuesday.

The quake at 1:50 p.m. caused no injuries and only light damage, which was confined to San Jose and nearby South Bay communities.

It shook some goods off shelves, broke some china, caused a minor fire, and interrupted the Polly Klaas murder trial on the sixth floor of the San Jose Hall of Justice for about 30 minutes. Scattered power outages also were reported.

The temblor occurred in one of the seismic hot spots that dot California.

U.S. Geological Survey seismologist Paul Reasenberg said that since 1968, there have been 92 earthquakes measuring at least magnitude 3.0 within a five-mile radius of Tuesday’s epicenter. The strongest was a 5.1 in 1988.

Reasenberg said the epicenter was on the creeping Alum Rock segment of the Calaveras fault. The term creeping refers to constant minor movement of a fault, usually punctuated by small and moderate quakes of the kind that occurred Tuesday.

The much stronger magnitude 7.1 Loma Prieta quake of 1989 occurred on the other side of San Jose in the Santa Cruz mountains near the larger San Andreas fault.

Reasenberg said there is a 35% chance of a Calaveras fault aftershock of magnitude 4 sometime in the next week, and a 5% chance of a larger quake, magnitude 5.0 or a little stronger.

He also noted that quakes have been edging northward along the Calaveras since 1979, when a 5.9 quake occurred near Coyote Lake south of San Jose.

In San Francisco, where Tuesday’s quake was felt as a rolling motion, all Bay Area Rapid Transit trains were stopped briefly for inspection of the tracks but no damage was found.

The quake was felt as far north as Santa Rosa, as far east of Sacramento and as far south as Monterey Bay.