BIG BEAR LAKE — A moderate earthquake jolted parts of Riverside and San Bernardino counties early Monday, within hours of an unrelated temblor in the San Francisco Bay Area. No damage or injuries were reported.
The Southern California quake, which struck at 8:10 a.m., measured 4.1 on the Richter scale and was centered four miles north of Big Bear Lake. It was felt as far away as Apple Valley in the desert and in San Bernardino, said Kate Hutton of the Caltech Seismological Laboratory.
"We've had a lot of calls and alarms, but no damage," said San Bernardino County Sheriff's Deputy Duane Lindquist. San Bernardino police, the Riverside County Sheriff's Department and the state Office of Emergency Services also reported no damage.
The quake, which was not associated with any known fault, occurred in a seismically active "wedge" of ground that slopes beneath the San Bernardino Mountains, said Lucile Jones, a seismologist with the U.S. Geological Survey in Pasadena.