Four earthquakes rattle California as voters go to polls on Super Tuesday, USGS says

Four earthquakes hit various parts of California as voters headed to the polls as for Super Tuesday primary elections, the U.S. Geological Survey reports.

A 6:46 a.m earthquake near Ridgecrest, where two large quakes hit in July, measured 2.7 magnitude, according to the agency.

A 7:01 a.m. earthquake in New Idria near Mendota and Coalinga measured 4.0 magnitude, the USGS says.

Two more earthquakes hit about 10 a.m. in Redwood Valley near Ukiah on the Northern California coast. The first, at 10:12 a.m., measured 2.9 magnitude, while the second, at 10:21 a.m., measured 3.6 magnitude, according to the USGS.

A 3.2-magnitude quake also shook the Ridgecrest area at 4:32 p.m. Monday, the agency says.

Magnitude measures the energy released at the source of an earthquake, the U.S. Geological Survey says. It replaces the old Richter scale.

Quakes between 2.5 and 5.4 magnitude are often felt but rarely cause much damage, according to Michigan Tech.