Earthquakes happen all the time
California is home to two-thirds of our nation's earthquake risk.
Since the magnitude 6.7 earthquake in Northridge in 1994, according to the
U.S. Geological Survey (USGS), California has experienced more than 1,170 earthquakes with a magnitude 4.0 or greater—including the 2014 magnitude 6.0 South Napa quake that caused widespread damage.
California has more than 2,000 known faults crisscrossing the state. But some of the world's most devastating earthquakes, such as the Northridge quake, have occurred on previously unknown faults.
As the magnitude 6.9 Loma Prieta earthquake of 1989 proved, sometimes the most extensive earthquake damage can occur many miles from the fault and epicenter. The
USGS reports that the most severe property damage occurred in Oakland and San Francisco—more than 60 miles from the epicenter in the Santa Cruz Mountains.
California's Earthquake History
The earliest recorded quake occurred in 1769 in the Los Angeles region during a land expedition led by Gaspar de Portolá. According to the diaries of the members of the expedition, the strong quake occurred on July 28, followed by several smaller quakes. Scientists believe this was a major earthquake, similar in size to the devastating 1933 Long Beach quake.
Source: LA Times
Some of the most damaging quakes in California history