Arizona vs Colorado Earthquake Risk

Colorado has a higher earthquake risk with a score of 4/10 (Moderate) compared to Arizona at 3/10 (Low-Moderate). This means Colorado faces more frequent and potentially more destructive seismic events.

Arizona averages approximately 20 earthquakes per year, while Colorado averages about 50 per year. Colorado experiences roughly 30 more earthquakes annually.

Arizona is associated with Basin and Range faults. Colorado is associated with Rio Grande Rift. 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 25% in Colorado. Colorado has a larger percentage of residents exposed to seismic hazard.

Arizona's most notable earthquake: 1887 Sonoran (M7.2, felt in AZ). Colorado's most notable earthquake: 1882 Northern Colorado (M6.6). These historical events illustrate the seismic potential of each state.