California vs Pennsylvania Earthquake Risk

California has a higher earthquake risk with a score of 10/10 (Very High) compared to Pennsylvania at 2/10 (Low). This means California faces more frequent and potentially more destructive seismic events.

California averages approximately 10,000 earthquakes per year, while Pennsylvania averages about 3 per year. California experiences roughly 9,997 more earthquakes annually.

California is associated with San Andreas, Hayward, San Jacinto, Cascadia. Pennsylvania is associated with Minor intraplate zones. 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 3% in Pennsylvania. California has a larger percentage of residents exposed to seismic hazard.

California's most notable earthquake: 1906 San Francisco (M7.9). Pennsylvania's most notable earthquake: 1994 Reading (M4.6). These historical events illustrate the seismic potential of each state.