4.1-magnitude quake follows weekend swarm in Southern California, seismologists say
A 4.1-magnitude earthquake shook the Imperial Valley in California following a swarm of smaller tremors, the U.S. Geological Survey reported.
The 7-mile deep quake hit 10 miles southeast of Ocotillo Wells at 5:17 a.m. Monday, May 20, according to the USGS.
More than 850 people from as far away as Azusa and Pasadena reported feeling the tremor to the agency.
The earthquake follows a swarm of smaller quakes just south of the Salton Sea, seismologists say.
“The current quakes in the Imperial Valley are being called a swarm,” seismologist Lucy Jones wrote Saturday, May 18, on X, formerly Twitter. “These have been common in the Imperial Valley.”
As of Saturday evening, Jones counted at least 16 quakes at 3.0 magnitude or higher in the region, she said.
Ocotillo Wells is about a 95-mile drive northeast of San Diego.
What to know about earthquakes
Magnitude measures the energy released at the source of the earthquake, the U.S. Geological Survey says. It replaces the old Richter scale.
Quakes between 2.5 and 5.4 magnitude are often felt but rarely cause much damage, according to Michigan Tech. Quakes below 2.5 magnitude are seldom felt by most people.
Earthquakes’ sudden, rapid shaking can cause fires, tsunamis, landslides or avalanches. They can happen anywhere, but they’re most common in Alaska, California, Hawaii, Oregon, Puerto Rico and Washington, according to the Department of Homeland Security.
If an earthquake strikes, it’s best to protect yourself right away. Here are tips from experts:
If you’re in a car: Pull over and stop. Set your parking brake.
If you’re in bed: Turn face-down and cover your head with a pillow.
If you’re outdoors: Stay away from buildings. Don’t go inside.
If you’re inside: Stay and don’t run outdoors. Stay away from doorways.
The best way to protect yourself during an earthquake is to drop, cover and hold on, officials say.
“Wherever you are, drop down to your hands and knees and hold onto something sturdy,” officials say. “If you’re using a wheelchair or walker with a seat, make sure your wheels are locked and remain seated until the shaking stops.”
Be sure to cover your head and neck with your arms, and crawl under a sturdy table if possible. If no shelter is available, crawl to an interior wall away from windows.
Once under a table, officials say you should hold on with one hand and be ready to move with it.
“There can be serious hazards after an earthquake, such as damage to the building, leaking gas and water lines, or downed power lines,” officials say. “Expect aftershocks to follow the main shock of an earthquake. Be ready to Drop, Cover, and Hold On if you feel an aftershock.”
This story was originally published May 20, 2024 at 7:57 AM with the headline "4.1-magnitude quake follows weekend swarm in Southern California, seismologists say."