US News3.6 Magnitude Earthquake Shakes Southern CaliforniaSaveMark Us Preferred on GooglePrintA 3.6 magnitude earthquake struck Riverside County, Calif., according to the U.S. Geological Survey (USGS) on Sept. 30, 2018. USGSJack PhillipsBreaking News Reporter9/30/2018|Updated: 9/30/2018A 3.6 magnitude earthquake struck Riverside County, California, according to the U.S. Geological Survey (USGS) on Sept. 30.The tremor shook the area at 7:41 a.m. local time, centered around 2 miles east-southeast of Calimesa. The quake’s depth is located at 10 miles.We had a problem loading this article. Please enable javascript or use a different browser. If the issue persists, please visit our help center.