1968 Illinois earthquake
1968 CE.
Shown on the map at 37.950°, -88.480°.
The U.S. Midwestern state of Illinois was struck by its largest recorded earthquake (a New Madrid event) in 1968. Striking at 11:02 a.m. on November 9, it measured 5.3 on the Richter scale. Although no fatalities occurred, the event caused considerable structural damage to buildings, including the toppling of chimneys and shaking in Chicago, the region's largest city. The earthquake was one of the most widely felt in U.S. history, largely affecting 23 states over an area of 580,000 sq mi (1,500,000 km2). In studying its cause, scientists discovered the Cottage Grove Fault in the Southern Illinois Basin. Within the region, millions felt the rupture. Reactions to the earthquake varied; some people near the epicenter did not react to the shaking, while others panicked. A future earthquake in the region is extremely likely; in 2005, seismologists and geologists estimated a 90% chance of a magnitude 6–7 tremor before 2055, likely originating in the Wabash Valley seismic zone on the Illinois–Indiana border or the New Madrid fault zone.
Text from the Wikipedia article 1968 Illinois earthquake, licensed CC BY-SA 4.0.