Dozens of small to moderate earthquakes rattled Southern California on Sunday, shaking an area from rural Imperial County to the San Diego coast and north into the Coachella Valley.
The largest quake, magnitude 5.3, struck at 12:31 p.m. (U.S time) about three miles north-northwest of the small Imperial County farming town of Brawley, according to Paul Caruso, a geophysicist with the U.S. Geological Survey. It was followed minutes later by a magnitude-4.9 quake.
The first quake had a magnitude of 3.9 and hit at 10:02 a.m. It was followed by a smaller quake about 90 seconds later in the same area near the southern end of the Salton Sea, and other smaller quakes followed within six minutes of the first shock.
Several glasses and a bottle of wine crashed to the floor and shattered at Assaggio, an Italian restaurant in Brawley, said owner Jerry Ma. The shaking was short-lived but intense, he said.
"It felt like there was quake every 15 minutes. One after another. My kids are small and they're scared and don't want to come back inside," said Mike Patel, who manages Townhouse Inn & Suites in Brawley. A TV came crashing down and a few light fixtures broke inside the motel, Patel said.
A Brawley Police Department dispatcher said several downtown buildings sustained minor damage. No injuries were reported.
The USGS said more than 100 aftershocks struck the same approximate epicenter, about 16 miles north of El Centro. Some shaking was felt along the San Diego County coast in Del Mar, some 120 miles from the epicenter, as well as in the Coachella Valley, southern Orange County and parts of northern Mexico.
USGS seismologist Lucy Jones said earthquake swarms are characteristic of the region, known as the Brawley Seismic Zone.
"The area sees lots of events at once, with many close to the largest magnitude, rather than one main shock with several much smaller aftershocks," Jones said.
The last major swarm was in 2005, following a magnitude-5.1 quake, she said.
Scientists weren't yet sure what fault Sunday's quake cluster was on, but it was near the 800-mile San Andreas Fault, Caruso said.