A moderate earthquake hit the Palm Springs area early Friday and was felt across parts of Southern California.

The U.S. Geological Survey says the magnitude 5.1 temblor struck at 1:04 a.m. PDT and was centered about 20 miles south of Rancho Mirage.

USGS geophysicist Amy Vaughan says there have already been a series of aftershocks.

She says that it was strong enough to likely have woken people up.

Facebook and other social media sites carried reports 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.