PALM SPRINGS, Calif. -- A moderate, shallow earthquake hit the Palm Springs area early Friday and was felt across parts of Southern California.

The U.S. Geological Survey says the magnitude 5.2 temblor, six-tenths-of-a-mile down, struck at 1:04 a.m. PDT and was centered about 20 miles south of Rancho Mirage.

CBS Palm Springs affiliate KESQ says a quake of that strength at that depth is capable of generating considerable damage.

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The California Highway Patrol said some drivers were reporting that boulders were on Highway 74 from Palm Desert to Pinyon, KESQ notes.

USGS geophysicist Amy Vaughan says the temblor touched off a series of smaller aftershocks. She says it was strong enough to likely have woken people up.

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

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

Rancho Mirage is in Riverside County, about 10 miles south of Palm Springs.

KESQ says quake was along the San Jacinto Fault, historically the most active fault in Southern California, according to seismologist Lucy Jones.

It was near a magnitude-6 earthquake in 1937 and a magnitude-5.3 earthquake in 1980, Jones reported. "We have never seen a San Andreas earthquake triggered by a San Jacinto earthquake,'' Jones wrote on Twitter, referring to the state's most famous fault.

"Every earthquake has a 5 percent of triggering an aftershock that is bigger than itself -- always within a few miles of location of the first earthquake,'' Jones wrote.