Two earthquakes struck just seconds apart on the Hawyard Fault near El Cerrito Monday morning, the U.S. Geological Survey said.
A 4.0 magnitude temblor struck near the Mira Vista Country Club in the El Cerrito hills at 5:33 a.m., eight seconds after a 3.5 quake hit a quarter-mile to the northeast. Each quake had a depth of 5 1/2 miles, the San Francisco Chronicle said.
The shaking was felt within a 60-mile radius, from Santa Rosa in the north to Santa Cruz in the south, a CBS report said.
A 2003 USGS report said the Hawyard Fault had the highest chance - 27 percent - of producing a large earthquake of magnitude-6.7 or higher in the Bay Area within 30 years.
"We know that the Hayward Fault is the really important fault in the Bay Area," USGS seismologist David Schwartz told KGO-TV on Monday. "These earthquakes, these 4's, are just an indication of ongoing activity, ongoing stress on the fault. They do nothing to relieve the liklihood of something larger happening."
Susan Torres, 72, who lives near the golf course, knew it was an earthquake immediately.
"It like thunder going through the house," she said. "I was thinking that the house was going to come down."
The Chronicle said the quakes gave Starbucks employees in El Cerrito a pretty good jolt.
"Everything was moving, for a minute maybe," an employee said who believed the quake was harder than a previous swarm of quakes centered in Berkeley last year.
Albany, El Cerrito and Richmond police dispatchers received no reports of injuries or major damage, the Chronicle said. In Berkeley, a water pipe at an apartment complex broke, causing minor water damage, a dispatcher said.