Arizona vs California Earthquake Risk

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

Arizona averages approximately 20 earthquakes per year, while California averages about 10,000 per year. California experiences roughly 9,980 more earthquakes annually.

Arizona is associated with Basin and Range faults. California is associated with San Andreas, Hayward, San Jacinto, Cascadia. These fault systems determine the type and frequency of seismic activity each state experiences.

In Arizona, approximately 15% of the population lives in areas at risk from earthquakes, compared to 98% in California. California has a larger percentage of residents exposed to seismic hazard.

Arizona's most notable earthquake: 1887 Sonoran (M7.2, felt in AZ). California's most notable earthquake: 1906 San Francisco (M7.9). These historical events illustrate the seismic potential of each state.