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.
1980 Eureka earthquake
The left-lateral strike-slip earthquake was the largest to occur in California since the 1952 Kern County earthquake. The mainshock (which was described as a multiple-rupture, with four subevents in the initial 80 seconds) and its aftershocks occurred on a northeast-trending fault that extended from near the Mendocino Fault to a point northwest of Eureka. Movement along the fault is due to a north-south compressional regime and the resulting intraplate deformation of the Gorda Plate. Previous events in this area were the January 1922 7.3 and the January 1923 7.2 shocks.