Shaking was observed throughout a wide area, including the coast, downtown Los Angeles, the San Fernando Valley, the South Bay, Riverside and Orange counties, and elsewhere.
A magnitude-4.6 earthquake northwest of Malibu generated widespread shaking that was felt early Friday afternoon from the coast to Southern California’s inland.
The quake occurred just before 2 p.m. near the Santa Monica Mountains, approximately 7 miles northwest of Malibu. Within an hour, more than a dozen aftershocks were reported in the same area, with the greatest magnitudes being 3.0 and 2.7.
“It’s got a very robust aftershock sequence,” said seismologist Dr. Lucy Jones, adding that the possibility of the quake being a foreshock to a larger seismic event fades over time.
Shaking was recorded throughout the greater Los Angeles area, maybe by up to 12 million people. The earthquake was felt along the beaches of Los Angeles, Orange, and Ventura counties, including the South Bay and Long Beach, as well as inland locations such as the San Fernando Valley, downtown Los Angeles, Riverside, Irvine, and Anaheim.
Some weak to light shaking was also felt in northern San Diego County.
Marla Dailey was working in a Thousand Oaks dentist clinic when she felt the shakes.
“It was a major jolt,” Dailey recalled. “We all figured out what was happening. The patients were fine, and they went forward with the dental. It is always a little nerve-racking.
There were no initial reports of extensive damage. The Los Angeles Fire Department was doing a damage survey, which is usual protocol following a larger magnitude earthquake.
The US National Tsunami Warning Centre claimed that no tsunami was triggered.
There are several earthquake faults in the vicinity, but Jones believes the quake occurred on the Malibu Coast Fault, which runs along the shoreline in the Santa Monica Mountains. The fault is near Pacific Palisades, Westwood, Beverly Hills, and Santa Monica. Its eastern end intersects the Santa Monica Fault.
The earthquake occurs on the same date as the catastrophic magnitude-6.5 earthquake in San Fernando in 1971. That historic quake killed dozens of people, caused over $500 million in property damage, and sparked worries of a possibly catastrophic dam collapse. The earthquake originated in the San Gabriel Mountains’ foothills north of Los Angeles, but it was felt throughout the San Fernando Valley.
Also on Friday, a magnitude-5.7 earthquake on Hawaii’s Big Island shook Oahu, including Honolulu. The earthquake was unrelated to seismic activity in Southern California.