The Virginia Seismic Zone has not had a history of regular earthquake activity. Earthquakes are rarely above 4.5 in magnitude, because Virginia is located away from the edges of the North American Plate. A 5.8 magnitude earthquake struck central Virginia on August 23, 2011, near Mineral, and was the Commonwealth's largest in at least a century. Due to the area's geologic properties, the earthquake was felt from Northern Florida to Southern Ontario. 35million years ago, a bolide impacted what is now eastern Virginia. The resulting Chesapeake Bay impact crater may explain what earthquakes and subsidence the region does experience. A meteor impact is also theorized as the source of Lake Drummond, one of just two natural lakes in the state.