LOCAL : 4.7-Magnitude Quake Hits Orange, San Diego Counties

A moderate earthquake, believed to be an aftershock of a temblor that struck almost four years ago, rattled Orange and San Diego counties early this morning. There were no reports of injuries or damage.

The 4.7-magnitude temblor struck at 1:54 a.m. and was centered off the San Diego County coast about 28 miles southwest of Oceanside. Robert Finn, spokesman for Caltech in Pasadena, said the jolt was an aftershock of a 5.3-magnitude earthquake in July, 1986.

“It’s relatively uncommon, but not amazingly uncommon, to experience an aftershock more than three years after the quake,” Finn said. “This is an aftershock even at this late date because the aftershock sequence has never decayed to the area’s normal background level.”

John Sims, a dispatcher with the Orange County Sheriff’s Department, said he fielded several calls from residents concerned about the earthquake. Sgt. Julie Sutton, a spokeswoman for the San Diego County Sheriff’s Department, said she had received about 25 calls.

Residents in south Orange County and north San Diego County seemed to feel the quake the hardest, with many reporting they were jolted out of bed by the temblor.

It was the third earthquake in fewer than 12 hours to strike California and followed a statewide earthquake-preparedness drill.

A 3.9-magnitude quake rolled through the desert and mountain communities of San Bernardino County at 7:13 p.m. Tuesday, Finn said.

Another temblor, put at a magnitude of 3.5, struck about 12 miles east of Cloverdale in Northern California at 2:15 p.m. Tuesday. No damage or injuries were reported from those earlier quakes.

On Monday, hundreds of Southland residents participated in “duck, cover and hold” drills organized by the state office of emergency services to prepare Californians for earthquakes.