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.
1992 Cape Mendocino earthquakes
As the largest earthquake in California since the October 1989 event in the Santa Cruz Mountains, the mainshock near Petrolia produced some of the highest ground motions ever recorded (at that time) by the California Strong Motion Instrumentation Program (CSMIP). Fourteen existing CSMIP stations comprising 84 strong motion sensors recorded the event, ten of which were ground response stations. The remaining four were located on structures, including a Highway 101 overpass in Rio Dell, a dam, a one-story supermarket in Fortuna, and a 5-story residential building in Eureka. The supermarket, residential building, and dam were 28, 50, and 75 kilometers distant from the epicenter respectively, and recorded peak accelerations of .46"g", .34"g", and .15"g". An accelerograph at the Painter Street overpass (a concrete bridge, from the epicenter) recorded a free field acceleration of .55"g" and an instrument on the structure saw an amplified peak of 1.23"g" during the mainshock.