YORBA LINDA, Calif. – Three small earthquakes rattled California's Orange County area over a period of less than four hours on Thursday. No damage was immediately reported.
The first quake, with a magnitude of 3.8, struck at 4:56 p.m. Thursday and was centered 2 miles northeast of the city of Yorba Linda, the U.S. Geological Survey reported.
Then a magnitude-4.0 quake struck at 8:27 p.m. and a 3.0 tremor followed less than a minute later. Seismologist Lucy Jones at the USGS office in Pasadena said the 3.0 quake was an aftershock of the 4.0.
"Each earthquake makes another earthquake more likely," she said.
Jones said the 4.0 occurred on a fault parallel to the Whittier Fault, a moderately active fault that stretches about 30 miles from eastern Los Angeles County south to northern Orange County.
The shaking occurred near the location of last year's magnitude-5.4 temblor, centered in neighboring Chino Hills, that rattled a large swath of Southern California. The area has had a series of mostly minor earthquakes since March.
Peter Chuang, manager of Wing's Chinese Restaurant in Yorba Linda, said the second quake shook for about 15 seconds.
"It felt very strong," Chuang said. "Some customers were very nervous and asked to take their food home so they could check on their houses."