California vs Massachusetts Earthquake Risk

California has a higher earthquake risk with a score of 10/10 (Very High) compared to Massachusetts at 3/10 (Low-Moderate). This means California faces more frequent and potentially more destructive seismic events.

California averages approximately 10,000 earthquakes per year, while Massachusetts averages about 5 per year. California experiences roughly 9,995 more earthquakes annually.

California is associated with San Andreas, Hayward, San Jacinto, Cascadia. Massachusetts is associated with Cape Ann seismic zone. These fault systems determine the type and frequency of seismic activity each state experiences.

In California, approximately 98% of the population lives in areas at risk from earthquakes, compared to 10% in Massachusetts. California has a larger percentage of residents exposed to seismic hazard.

California's most notable earthquake: 1906 San Francisco (M7.9). Massachusetts's most notable earthquake: 1755 Cape Ann (M6.0). These historical events illustrate the seismic potential of each state.