Magnitude 5.2 earthquake strikes at 1 a.m. PST

A moderately large earthquake rocked rural Southern California nearly 30 miles south of Palm Springs. The epicenter was in the desert.

The U.S. Geological Survey says the magnitude-5.2 temblor struck just after 1 a.m. Friday. USGS geophysicist Amy Vaughan says it was strong enough to have awakened sleepers. She says the shallow quake touched off a series of smaller aftershocks, registering between magnitude-2.6 to 3.6.

The Los Angeles County Fire Department and the Riverside County Sheriff's Department say they had no reports of damage.

Initial incomplete data had suggested two quakes of roughly the same size shook within a minute, but USGS deleted one of them shortly afterward.

California is an earthquake-prone region because it is located along what geologists call the Ring of Fire surrounding the Pacific Ocean.

Dr. Lucy Jones – a geologist in southern California – has posted many tweets about the June 10 earthquake this morning. Among them:

"We have never seen a San Andreas EQ triggered by a San Jacinto EQ. The 2 faults are ~25 miles apart"

Facebook and other social media sites carried posts from people in San Diego and Los Angeles, about 100 miles to the west, reporting they felt the quake.