无数多年了? Last month SF had two

The U.S. Geological Survey reported that a magnitude-3.5 quake struck at 5:33 a.m. about eight miles northeast of San Francisco in the city of El Cerrito. It was followed eight seconds later by a magnitude-4.0 temblor, said geophysicist Paul Caruso. The USGS originally reported that the first quake had a magnitude of 2.9.

The shaking was felt within a 60-mile radius, from Santa Rosa in the north to Santa Cruz in the south.