Andreanof Islands Earthquake

Date: March 9, 1957 • Location: Aleutians West Census Area, United States

The Andreanof Islands earthquake struck Hawaii and the Aleutian Islands, causing more than $5 million in damage from ground movement and a destructive tsunami.

The 1957 Andreanof Islands earthquake occurred at 04:22 local time on March 9 with a moment magnitude estimated at 8.6 and a maximum Modified Mercalli intensity of VIII (Severe). It occurred south of the Andreanof Islands group, which is part of the Aleutian Islands arc. The event occurred along the Aleutian Trench, the convergent plate boundary that separates the Pacific plate and the North American plates near Alaska. A basin-wide tsunami followed, with effects felt in Alaska and Hawaii, and strong waves recorded across the Pacific rim. Total losses were around $5 million.