On February 9, 2024, a magnitude-4.6 earthquake struck northwest of Malibu in Southern California. The quake was noticeable across a broad area, including the coast, downtown Los Angeles, the San Fernando Valley, South Bay, Riverside, Orange counties, and other inland regions.
The earthquake was reported just before 2 p.m. and occurred about 7 miles northwest of Malibu in the Santa Monica Mountains. Following the initial quake, more than a dozen aftershocks with magnitudes ranging from 3.0 to 2.7 were reported within an hour in the same area.
Seismologist Dr. Lucy Jones characterized the aftershock sequence as “very robust” and mentioned that the likelihood of the quake being a foreshock to a larger seismic event decreases over time.
Approximately 12 million people throughout the greater Los Angeles area, spanning from the coasts to inland regions like Long Beach, San Fernando Valley, downtown LA, Riverside, Irvine, and Anaheim, reported feeling the shaking. Some weak to light shaking was also reported in parts of north San Diego County.
Despite the significant jolt, there were no immediate reports of major damage, and the Los Angeles Fire Department conducted a standard damage survey. The U.S. National Tsunami Warning Center confirmed that no tsunami was triggered by the earthquake.
The earthquake possibly occurred along the Malibu Coast Fault, which runs along the coastline in the Santa Monica Mountains, near communities such as Pacific Palisades, Westwood, Beverly Hills, and Santa Monica. The eastern end of the Malibu Coast Fault intersects with the Santa Monica Fault.
Interestingly, this earthquake coincided with the anniversary of the deadly magnitude-6.5 1971 San Fernando earthquake, which resulted in numerous fatalities and extensive property damage.
In addition to the Southern California earthquake, there was a separate magnitude-5.7 earthquake on Hawaii’s Big Island on the same day, unrelated to the seismic activity in Southern California.