INDIO, Calif. –
The ground near Indio continues to tremble days after Monday’s magnitude 4.9 earthquake, with seismologists recording more than 440 aftershocks as of Thursday afternoon.
While the frequency of significant shaking has decreased since a sharp magnitude 4.3 jolt early Wednesday, the U.S. Geological Survey (USGS) data shows a steady progression of micro-quakes in the area. The most recent tremors, recorded Thursday, have been small, mostly measuring below magnitude 2.0.
Sequence Update The seismic activity remains clustered in the desert terrain roughly 12 miles (20 kilometers) north-northeast of Indio, near the southern edge of Joshua Tree National Park.
Key events in the timeline include:
– Monday, 5:56 p.m.: The sequence began with the main magnitude 4.9 earthquake.
– Wednesday, 12:30 a.m.: The largest aftershock, a magnitude 4.3 event, struck the same area.
– Thursday: Activity has consisted primarily of small tremors, with no events exceeding magnitude 3.0 recorded in the last 24 hours.
Expert Analysis Seismologists advise that while aftershock sequences typically decay over time, larger “trigger” events can occasionally occur days or weeks later. Shallow quakes like these-occurring at depths of roughly 2 to 4 miles-are often felt more acutely by local residents than deeper events.
Preparedness With the region remaining seismically active, emergency officials continue to urge preparedness. Residents are reminded to secure heavy furniture and keep emergency supplies accessible. In the event of another strong quake, the “Drop, Cover, and Hold On” protocol remains the recommended safety action.
