4.3 Magnitude Earthquake Strikes Southern California
on Jul 31, 2025
An Earthquake Was Felt Across The Inland Empire Thursday
A 4.3-magnitude earthquake struck the Muscoy area of the Inland Empire in Southern California shortly after 9:30 a.m. Thursday, according to the U.S. Geological Survey (USGS). The quake was shallow, originating just over three miles deep, and was felt across much of Southern California.
About an hour earlier, the Rialto area experienced two smaller quakes, one measuring magnitude 3.0, followed by a 2.8. Then, just minutes after the 4.3 quake, a 3.1-magnitude temblor shook the Rialto area again.
“This is an active area… This area is also near where the San Jacinto fault, which is one of the major Southern California faults, comes up and meets the San Andreas. So this is an area where we see seismicity, especially the magnitude 4s,” Dr. Gabrielle Tepp, a seismologist at Caltech, said of the quake.
Southern Californians React To The Quake
Residents of the surrounding areas took to ABC’s social media to report what they had felt from the earthquake, with many describing the incident as more of a “jolt.”
“That was a big jolt! No rolling feeling just a shake and jolt,” one user said.
“Felt it in Riverside rolling than shake,” another commented.
8.8 Magnitude Earthquake Threatens West Coast Over The Weekend
The jolt comes just a few days after an 8.8 earthquake struck off the Kamchatka Peninsula of Russia.
The West Coast of the United States and Guam were under a tsunami advisory, with the West Coast seeing waves hit the shore as early as 11:40 p.m. (PST), according to Fox Weather.
According to the Office of the Governor of Hawaii, the first wave was expected to hit Hawaii by 1:17 p.m. (HST) on July 30.
The tsunami warning in Hawaii was downgraded to an advisory by 10:39 p.m. (HST), after evacuations of residents to higher ground were conducted.
The earthquake was the most powerful recorded since 2011, when a 9.0 magnitude earthquake struck in the sea off the coast of Japan, leading to the Fukushima Daiichi Nuclear Power Station disaster.
