- The earthquake struck just before midnight, affecting large parts of Southern California and Mexico
San Diego residents were awakened just before midnight by a 4.8 magnitude earthquake that shook the city and surrounding areas.
The earthquake prompted dozens of locals to flood social media to check if others had felt the shaking.
According to the US Geological Survey, the earthquake occurred in Imperial County, close to the California-Mexico border. The epicenter was about 100 miles east of San Diego.
A map from the USGS showed that the earthquake affected much of Southern California, reaching into Mexico's Baja California region.
There were no immediate reports of injuries or damage.
The earthquake struck just before midnight, affecting large parts of Southern California and Mexico
A map from the US Geological Survey showing the communities affected by the earthquake
A map illustrating the level of shaking in the affected areas
One resident wrote on X: “Felt it in Mission Valley. My bed shook. It woke me up.' Another joked: “I live near San Ysidro and felt my couch moving, I thought I was just dizzy!”
While another said: 'Woke my wife up in Carmel Valley and of course she's freaking out.'
Every year in California, millions of people participate in ShakeOut, a statewide preparedness program.
ShakeOut's earthquake drills are coordinated by the Southern California Earthquake Center at the University of Southern California.
The event focuses on the 'drop, cover and hold' mantra for basic personal safety, but also includes measures such as passenger trains running slower by several minutes.
“We really encourage people to make themselves less of a target for things that cause injury,” said Mark Benthien, SCEC communications director and lead organizer of ShakeOut.
The ShakeOut exercise originated in California in 2008. The first was based on a scenario of a magnitude 7.8 earthquake in the southern part of California's mighty San Andreas Fault. It's the kind of catastrophic earthquake that experts warn will happen one day — though they can't say when.
The drill has since expanded internationally. Schools, government organizations, companies and others register to participate. More than 10 million people were registered in California this year, and millions more worldwide, organizers said.
Compared to 15 years ago, Benthien said, “many, many more people are preparing and practicing earthquake safety every year thanks to ShakeOut.”