1960 Valdivia earthquake
The 1960 Valdivia earthquake () or Great Chilean earthquake ("Gran terremoto de Chile") of 22 May is the most powerful earthquake ever recorded. Various studies have placed it at 9.4–9.6 on the moment magnitude scale. It occurred in the afternoon (19:11 GMT, 15:11 local time), and lasted approximately 10 minutes. The resulting tsunami affected southern Chile, Hawaii, Japan, the Philippines, eastern New Zealand, southeast Australia and the Aleutian Islands.
1968 Illinois earthquake
The 1968 Illinois earthquake (a "New Madrid event") was the largest recorded earthquake in the U.S. Midwestern state of Illinois. Striking at 11:02 a.m. on November 9, it measured 5.4 on the Richter scale. Although there were no fatalities, 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, affecting 23 states over an area of . In studying its cause, scientists discovered the Cottage Grove Fault in the Southern Illinois Basin.