Strong Earthquake Rattles SoCal, Several Smaller Quakes Follow

EL CENTRO, CA — A magnitude 4.8 earthquake struck northwest of El Centro early Monday morning and was immediately followed by a series of other quakes.

The first quake was recorded at 12:36 a.m. and was followed by 15 more 2.5+ magnitude quakes between 12:38 and 2:18 a.m. in the El Centro and Imperial areas of Southern California, according to the United States Geological Survey.

The first quake was centered about 1.8 miles north-northwest of El Centro, according to the USGS. It was reported roughly 11.7 miles deep. The largest aftershock was a 4.5-magnitude quake that shook about 1.2 miles northwest of El Centro.

Residents reported feeling the initial quake across San Diego County, including in Alpine, Chula Vista, Coronado, Imperial Beach, La Mesa, Oceanside, Poway and Santee, according to the USGS's "Did You Feel It?" map. The shaking was felt as far away as Palm Desert in Riverside County and Aliso Viejo in Orange County, as well as in Yuma, Arizona.

The earthquake activated the USGS ShakeAlert Earthquake Early Warning System, which detects significant quakes early enough so that alerts can be delivered to residents and automated systems potentially seconds before shaking arrives. The early warning system estimated the quake above magnitude 5.0, so alerts were sent to cell phones through apps such as MyShake and ShakeReadySD, according to the USGS.

The earthquake swarm was one of the strongest to hit Southern California in years.

The series of quakes came just two days after a magnitude 4.6 quake struck near Malibu, which was also followed by a smaller swarm of quakes.

There were no initial reports of injuries or damage.

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