Southern California Earthquake: Magnitude 4.3 Rocks Region, Tremors Felt in LA

Early on Wednesday morning, an earthquake of magnitude 4.3 shook Southern California, with its center close to Muscoy, just north of San Bernardino. The earthquake occurred at approximately 9:32 a.m. and was felt all over the region, from Philadelphia to Los Angeles, as far north as Bakersfield, and as far south as the area around San Diego. Residents in Riverside and San Bernardino counties, as well as in Koreatown and Pasadena, reported light to moderate shaking.

The “Fontana trend,” a northeast-striking fault line beneath the sediments of the San Bernardino Valley that is believed to be a left-lateral strike-slip fault south of the San Gabriel Mountains, was the site of the earthquake and a small swarm of seismic activity. Aftershocks, including a 3.1-mag earthquake close to Rialto, quickly followed this event, which came after foreshocks of magnitudes 3.0 and 2.8.

Reports show little damage with no injuries or major structural impacts, despite the noticeable shaking felt over a wide area. Immediately following the earthquake, local emergency services confirmed that there were no damage calls. There has been a history of earthquakes in the area, including a larger 5.2 magnitude earthquake in 1970 and a 4.2 magnitude event that occurred close by last year.

Experts advise residents to be ready for future, possibly larger earthquakes and remind them that Southern California is an active seismic zone.

• Location & Magnitude: 4.3 north of San Bernardino, close to Muscoy

• Time: Wednesday morning, around 9:32 a.m.

• Shaking Feeling: Pervasive from Bakersfield in the north to San Diego in the south, including areas of Los Angeles

• Aftershocks: Multiple aftershocks, largest about 3.1 magnitude shortly after main quake

• Fault: Fontana trend, a fault beneath the San Bernardino Valley’s sediments

• Impact: No serious injuries or damage have been reported.

• Historical Context: An earthquake-prone region with a history of significant shocks

• Safety Reminder: Promotes preparedness for California’s upcoming seismic activity