1968 Illinois earthquake
The 1968 Illinois earthquake was the largest recorded earthquake in the U.S. Midwestern state of Illinois. It measured 5. 4 on the Richter scale, affecting 23 states over an area of 580,000 sq mi. The earthquake was felt in 23 states and affected a zone of around 300 million years ago. Scientists discovered the Cottage Grove Fault in the Southern Illinois Basin....