5.2-magnitude earthquake strikes Southern California, in San Diego County

An earthquake with a preliminary magnitude of 5.2 struck Southern California on Monday morning.

According to experts at the California Institute of Technology's Seismological Laboratory, the quake occurred around 10:08 a.m. PT in Julian, California.

According to the USGS map, the earthquake was felt throughout Southern California and into Mexico.

A 3.3 magnitude foreshock occurred shortly before 4 p.m., before the earthquake. Dr. Lucile Jones, a seismologist at Caltech, said on a teleconference after the quake.

According to Dr. Lucy Jones, this earthquake was most likely caused by the Elsinore Fault, a branch of the greater San Andreas Fault system. According to Jones, the quake occurred around eight miles below the Earth's surface.

Jones said Sunday's 3.3-magnitude earthquake in the same location was a precursor to Monday's 5.2-magnitude quake.

Tremors were reported over most of the state, from San Diego to Los Angeles. California Governor Gavin Newsom has been briefed on the earthquake, according to his office.

“The state is coordinating with local authorities to assess any damage and if emergency response is needed,” Newsom’s office said.

According to USGS earthquake modeling, individuals nearest to the epicenter felt "moderate shaking," while more than 25 million people experienced "weak to light shaking."

Scientists cannot tell if Monday's earthquake will presage a greater catastrophe, Jones added.

“Every earthquake could be a foreshock to something bigger,” she said, adding there’s typically a 5% chance an earthquake could be followed by another, stronger tremor.

The Los Angeles Fire Department examined the city by land, air, and sea, and there have been no reports of major structural damage or casualties.

It is unclear whether there have been any reports of injuries or damage.