Illinois vs Pennsylvania Earthquake Risk

Illinois has a higher earthquake risk with a score of 5/10 (Moderate) compared to Pennsylvania at 2/10 (Low). This means Illinois faces more frequent and potentially more destructive seismic events.

Illinois averages approximately 30 earthquakes per year, while Pennsylvania averages about 3 per year. Illinois experiences roughly 27 more earthquakes annually.

Illinois is associated with New Madrid, Wabash Valley seismic zones. Pennsylvania is associated with Minor intraplate zones. These fault systems determine the type and frequency of seismic activity each state experiences.

In Illinois, approximately 15% of the population lives in areas at risk from earthquakes, compared to 3% in Pennsylvania. Illinois has a larger percentage of residents exposed to seismic hazard.

Illinois's most notable earthquake: 1968 Southern Illinois (M5.4). Pennsylvania's most notable earthquake: 1994 Reading (M4.6). These historical events illustrate the seismic potential of each state.