A magnitude 7.1 earthquake hit Ridgecrest, California, Friday, rattling residents in Southern California.
The earthquake struck at 8:16 p.m. as part of an earthquake swarm in the Searles Valley, according to the U.S. Geological Survey. The earthquake struck nearly 9 miles west-southwest of Searles Valley and was felt as far away as Arizona.
"Every earthquake makes another earthquake more likely," said seismologist Dr. Lucy Jones. "Yesterday's 6.4 is now a foreshock, and that 7.1 aftershock has become the main shock."
In Kern and San Bernardino counties, officials reported cracked buildings and injuries. Urban Search and Rescue teams from LA and Orange counties were being deployed to Kern County to help with the damage there as they deal with a backlog of calls.
Others took to social media moments after the quake to describe the shaking.
NBC 7 reporter Erika Cervantes said she was at her parents house in L.A. when she felt the shaking.
NBC 4 Los Angeles reporter Jonathan Gonzalez, took video of a sign moving during the shaking.
"It felt so strong here in Murrieta. Made me nauseous, it lasted so long," said Facebook commenter, Cristina Bon.
San Diegans shared similar reactions following Thursday's earthquake. No damage in San Diego was immediately reported.
North County Transit officials said that Coaster and Sprinter passengers should expect a delay of up to 60 minutes while they inspect the tracks. They also said that trains will proceed at restricted speeds.
Yesterday's 6.4 foreshock was centered in Searles Valley, about 150 miles north of Los Angeles at about 10:30 a.m.
A magnitude-7.2 earthquake struck near Guadalupe Victoria, Mexico, about 45 miles south of Calexico, California, on Easter Sunday in 2010.
The jolt shifted the Earth's crust near the epicenter about 10 feet, according to radar images and data collected by researchers at NASA's Jet Propulsion Laboratory.
Calexico was the U.S. area hardest hit by the earthquake. No injuries were reported but some buildings suffered broken windows and cracked masonry.
To know what you need to do before, during and after an earthquake click here.
Also, learn what to keep in a disaster supply kit, which is a collection of basic items in your household that you may need in the event of an emergency.