INDIO, Calif. — A sharp magnitude 4.3 earthquake struck the Coachella Valley early Wednesday morning, the strongest aftershock yet in a restless seismic sequence triggered by Monday’s magnitude 4.9 event.
The magnitude 4.3 tremor occurred at 12:30 a.m. Wednesday, centered approximately 20 miles north-northeast of Indio, according to data from the U.S. Geological Survey (USGS). It had a shallow depth of about 2.3 miles (3.7 kilometers), causing shaking that was likely felt throughout Riverside and San Diego counties.
This latest quake is part of an ongoing series of more than 350 aftershocks recorded since the main event shook the region on Monday.
Monday’s Main Event The sequence began with a magnitude 4.9 earthquake at 5:56 p.m. Monday. That initial quake was also centered 20 miles north-northeast of Indio at a depth of roughly 1.9 miles (3.1 kilometers).
Seismologists note that shallow earthquakes—those occurring within the top few miles of the Earth’s crust—often produce more intense surface shaking than deeper events of the same magnitude.
Aftershock Sequence Since Monday evening, the USGS has recorded a flurry of seismic activity in the area. As of Wednesday afternoon, the sequence included:
One aftershock of magnitude 4.3 (Wednesday morning).
Four aftershocks between magnitude 3.0 and 3.9.
Hundreds of smaller micro-quakes.
The aftershocks have remained tightly clustered around the initial epicenter. The second-largest event, a magnitude 3.8 temblor, occurred shortly after the main shock on Monday evening.
Safety Reminders With seismic activity continuing, emergency officials remind residents to remain prepared. In the event of shaking, drop to the floor, take cover under a sturdy desk or table, and hold on until the shaking stops.
