California straddles the boundary between the Pacific and North American plates. The San Andreas, Hayward and San Jacinto faults produce thousands of small quakes every year. The 1906 San Francisco earthquake (M7.9) and the 1994 Northridge earthquake (M6.7) are among the most destructive in U.S. history. Scientists estimate a 70% chance of a major Bay Area quake within 30 years.
Data source: USGS Earthquake Hazards Program. Enable JavaScript for the live interactive map.