Imperial County was hit by a swarm of earthquakes Saturday, the largest one measuring magnitude 5.2, but there were no immediate reports injuries or major damage.
Quake swarms are not unusual for this border region. But the magnitude 5.2 quake is considered moderate.
The biggest quake in the swarm was felt across Imperial County, in San Diego and in parts of the Inland Empire. The U.S. Geological Survey said some people as far away as Los Angeles felt it.
“The Imperial County Fire Department and Office of Emergency Services is currently monitoring an assessing recent earthquake activity in our region,” Imperial County said on Twitter. “There has not been any report of damages yet and our crews are conducting damage assessments.”
The earthquake swarm appeared to strike in the southern end of the Brawley Seismic Zone, a seismically active region where tectonic plates are moving away from each other. The area sees regular seismic activity including swarms of hundreds of quakes. The Brawley Seismic Zone is particularly important to watch because it is the region that connects the San Andreas and Imperial faults, both of which can produce damaging earthquakes.
“Quakes in the Imperial Valley often come in swarms. Which continue until they stop,” earthquake expert Dr. Lucy Jones said on Twitter. A “potentially bigger quake is ALWAYS possible to be triggered by any quake. Happens 5% of the time.”
She added the quake appears to be along the Westmoreland fault.
The magnitude 5.2 earthquake was reported at 10:55 a.m. Pacific time nine miles from Brawley.
There have been scores of aftershocks, including several measuring 4.0 and greater.
The earthquake occurred 18 miles from Imperial, 22 miles from El Centro, 30 miles from Calexico and 45 miles from Coachella, Calif.
In the last 10 days, there have been 11 earthquakes of magnitude 3.0 or greater centered nearby.
An average of five earthquakes with magnitudes between 5.0 and 6.0 occur per year in California and Nevada, according to a recent three-year data sample.
The earthquake occurred at a depth of 3.6 miles. Did you feel this earthquake? Consider reporting what you felt to the USGS.
Find out what to do before, and during, an earthquake near you by reading our five-step earthquake preparedness guide.
This story was automatically generated by Quakebot, a computer application that monitors the latest earthquakes detected by the USGS. A Times editor reviewed the post before it was published. If you’re interested in learning more about the system, visit our list of frequently asked questions.