The latest quake is part of what geologists are calling an “earthquake sequence” It follows a 6.4-magnitude quake that struck the same area the day before LOS ANGELES: A 7.1-magnitude earthquake hit southern California on Friday at 8:19 p.m. (0319 GMT Saturday), the United States Geological Survey said. The latest quake is part of what geologists are calling an “earthquake sequence” and follows a 6.4-magnitude quake that struck the same area the day before.