Alaska earthquake of 1964, earthquake that occurred in south-central Alaska on March 27, 1964, with a moment magnitude of 9.2. It released at least twice as much energy as the San Francisco earthquake of 1906 and was felt on land over an area of almost 502,000 square miles (1,300,000 square km). The death toll was only 131 because of the low density of the state’s population, but property damage was high.
The earthquake tilted an area of at least 46,442 square miles (120,000 square km). Landmasses were thrust up locally as high as 82 feet (25 metres) to the east of a line extending northeastward from Kodiak Island through the western part of Prince William Sound. To the west, land sank as much as 8 feet (2.5 metres). Extensive damage in coastal areas resulted from submarine landslides and tsunamis. Tsunami damage occurred as far away as Crescent City, California. The occurrence of tens of thousands of aftershocks indicates that the region of faulting extended about 620 miles (1,000 km) along the North Pacific Plate subduction zone.