Pair of earthquakes – 3.5 and 3.9 – near Ontario jolts parts of Southern California

A pair of earthquakes hit Southern California on Saturday morning, Sept. 7, with the second one packing more of a jolt.

At 10:34 a.m., a 3.9-magnitude quake hit 4.4 miles east, southeast of Ontario, 4.7 miles north, northwest of Eastvale, 4.7 miles west, northwest of Jurupa Valley and 5.3 miles south of Rancho Cucamonga, the the U.S Geological Survey reported.

Today we are having a small swarm in the Fontana Seismicity Lineation, a northeast-striking line of many small quakes. Today we have so far M3.9, M3.5 and many M1s and M2s. I've seen this tyoe of cluster in Fontana dozens of times in my decades watching SoCal quakes.

— Dr. Lucy Jones (@DrLucyJones) September 7, 2024

 

The first quake, at 10:05 a.m., was centered 4.3 miles southeast of Ontario, 4.4 miles north-northwest of Eastvale, 4.9 miles west, northwest of Jurupa Valley and 5.5 miles east of Chino, according to the USGS’s preliminary report.

Both the foreshock and the quake that followed occurred at a depth of about three miles.

No injuries or damage were immediately reported.

The more intense quake was felt mostly in Riverside and Orange counties but also in Long Beach and West Covina, according to the USGS.

Shortly before noon, a less noticeable, 2.6-magnitude quake was recorded 2.4 miles southeast of Ontario, the agency said.