A swarm of earthquakes, hundreds in total, that began to shake the Salton Sea area in Imperial County Wednesday afternoon continued Thursday and could last for another few days, according to a geologist. The swarm was centered in Westmorland, and the first earthquakes were felt at about 4 p.m. By the evening there were about 284 earthquakes in Imperial County. By Thursday afternoon, that number was more than 700, the majority minor quakes with magnitudes in the 1.2 range.
Pat Abbott, professor emeritus at San Diego State’s Geological Sciences Department, says the swarm is evidence of San Diego and Baja California pulling away from mainland Mexico and the United States. The largest quake was a magnitude 4.9, a little after 5:30 p.m. Wednesday that was felt in parts of San Diego County and Tijuana, according to United States Geological Survey.
Abbot said “This area is famous for seismic swarms, so what we’re getting here is stunning, the numbers, but this is not a rare event there at all. This can happen every year, every few years, and it has throughout our seismological records. We call it the Brawley Seismic Zone.”
Seismologist Dr. Lucy Jones said, “The swarm happening now south of the Salton Sea, near Westmoreland, is over 30 km south of the end of the San Andreas,” said. “It is in the Brawley seismic zone, a common source of swarms …. too far from the San Andreas to change the probability of a quake on it.”
