A 3.4-magnitude Compton earthquake struck near Ontario in Southern California’s Inland Empire around 5:37 am Wednesday, sending light shaking across several communities. The USGS placed the epicenter about 3.7 miles southeast of Ontario, with no immediate reports of damage.
Residents in Irvine, Anaheim, Menifee, Riverside, San Bernardino and West Covina reported shaking. The USGS Felt Report received 226 responses, and most people described the movement as light.
Ontario in Southern California
The quake was about 12.5 miles east of Riverside and roughly 4 miles deep. That shallow depth helped make a small quake noticeable well beyond Ontario, even as the strongest reports stayed in the light range.
Another report placed the epicenter about 4 miles southeast of Ontario. The difference is small, but both locations point to the same part of the Inland Empire where the shaking began.
USGS Felt Report
The USGS Interactive Map showed shaking reports across Southern California, and San Bernardino County officials asked residents whether they felt the tremor. County officials also posted on Instagram asking people to report if they experienced the earthquake.
For people in the affected communities, the immediate question is whether their own area was among those that reported shaking. The available reports point to light movement rather than damage, so the practical next step is to check local surroundings and use the USGS Felt Report if they experienced the quake.
San Bernardino County
The wider spread of reports, from Ontario to Irvine and Anaheim, shows why a modest quake can still draw attention across a broad part of Southern California. The open question is why the shaking reached so many places despite the 3.4 magnitude, and the answer will depend on how the USGS and local reports line up with the shallow depth and the felt responses.
