Parts of State Rattled by 3 Mild Quakes

A moderate earthquake shook the San Francisco Bay Area early Sunday evening, capping a day in which two lesser temblors hit San Bernardino and Napa counties--all in less than 4 1/2 hours.

No injuries or major damage were reported in any of the quakes, but all three shook groceries from shelves and nappers from their slumber.

The Bay Area episode, on the Calaveras Fault northeast of San Jose, was powerful enough to cause shoppers to gasp and cry out in San Francisco, 45 miles away, and was felt as a sharp nudge by people in San Rafael, 65 miles distant.

The UC Berkeley seismology station and the National Earthquake Information Service in Golden, Colo., both pegged the 6:46 p.m. Bay Area quake at magnitude 5.1. The U.S. Geological Survey in Menlo Park, 30 miles south of here, estimated it at 5.3.

A 2:25 p.m. quake centered near Ontario was estimated at magnitude 3.4, and was followed 19 minutes later by a 3.3 quake near Lake Berryessa in Napa County, about 60 miles northeast of San Francisco.

Scientists did not say whether there was a relationship among any or all of the temblors, which stretched along a 450-mile axis parallel to the coast.

Earthquakes registering 3.5 are believed to be capable of “slight” damage in the immediate area. Those in the 5.0 range are thought capable of “considerable” damage.

‘Strongest Quake’

“It was the strongest quake I’ve felt here in years,” said Mike Pechner, a weatherman for San Francisco radio station KNBR.

Nearer the epicenter, at the UC Santa Cruz Lick Observatory on Mt. Hamilton, telescope technician Jim Burrous said the effects were not severe.

“Things just shook a little, about five or six seconds of gentle shaking and swaying,” he said. “These are old wooden buildings, and they pretty much ride these things out.”

Ironically, Burrous said, the observatory, now celebrating its centennial, is being partly rebuilt to repair damage to its main building by another earthquake along the same fault in 1984.

Inland Empire Affected

The Ontario-area quake also was felt in San Bernardino, Fontana and Riverside, about 50 miles east of Los Angeles.

“We thought someone had hit the building. We only got about two or three calls on it,” Fontana Police Dispatcher Teresa Paniagua said.

“I felt a jolt,” said Ontario Police Lt. Lloyd Scharf, who was in the police station at the time. “But it didn’t seem that big because it hit once. I just continued watching the Laker game.”

It was the second widely felt temblor to hit the Southland since Friday, when a shaker measuring 5.2 hit the Gorman area, 40 miles northwest of Los Angeles. That temblor led to the closure of the 440-mile California Aqueduct when it damaged electrical equipment at a pumping plant.