A swarm of earthquakes, including one that measured at a magnitude of 5.3, rattled the area near the Salton Sea in Imperial County Saturday, according to the U.S. Geological Survey.
The strongest quake struck at 10:55 a.m. at a depth of 5 km nearly 7 miles from Calipatria, about 9 miles from Niland and 24.9 miles from El Centro.
The shaking was felt in San Diego, Oceanside, Escondido and across the U.S. border with Mexico, according to USGS.
The earthquake followed a series of smaller tremors, with preliminary magnitudes 4.6, 4.3, 4.1 and 4.0. They were all reported in the same area within ten minutes of the stronger 5.3 quake.
Seismologist Dr. Lucy Jones said earthquakes in the Imperial Valley often come in swarms.
As of 12:17 p.m., the swarm had included 24 quakes with magnitudes greater than 3.0, Jones said. The main fault appears to be the Westmoreland fault, which is not long enough for a quake much bigger than a magnitude 5.8, she added
“And there is no way to be sure what is coming next,” the seismologist wrote. “As long as it stays active, there will be more quakes and some could be large. Many of the swarms have a ~M5 as the largest. Rarely, they grow to include a M5.8-6.0”
The quakes could trigger other faults, but that is much less likely, Jones said.