Sunday night’s 4.2 magnitude earthquake felt across the Westside of Los Angeles was centered in the Santa Monica Mountains.
After initially calculating that the temblor was probably an aftershock of a 4.4 magnitude March 17 quake, seismologist Lucy Jones of the U.S. Geological Service said that further analysis of the quake showed that it was not located in the same zone as other aftershocks, and was thus probably a separate event.
Like the March event and a magnitude 2.5 quake in Beverly Hills, she added, Sunday night's quake occurred in the Santa Monica Mountains -- near but not on the Santa Monica-Hollywood fault.
The earthquake was the third above magnitude 4 in the last three months, she said. "It’s not unprecedented, but it’s quite a bit more than we’ve had recently," she said. "It's a good reminder to be prepared."
As of 8:45 p.m., 2,310 people in 145 zip codes had reported to the U.S. Geological Service's "Did You Feel It" website. A few reported feeling weak shaking as far west as Ventura, as far south as Hermosa Beach and as far east as Sylmar. A larger number in parts of the central San Fernando Valley such as Tarzana, Encino and Van Nuys reported slightly stronger shaking.
Shortly after the quake, the Los Angeles Fire Department entered "Earthquake Mode," said department spokesman Erik Scott -- a process during which firefighters from all 106 neighborhood fire stations survey more than 470 square miles in the greater Los Angeles area, looking for damage, injuries or possible threats to safety from compromised infrastructure including freeway overpasses) or downed power lines.