The Great Alaska Earthquake and Tsunami of 1964

On 27 March 1964, an earthquake of the reported magnitude 9.2 occurred on a fault between the Pacific and North American plates. It shook Alaska’s environment surrounding Prince William Sound and left a footprint of destruction behind. Throughout the day after the initial jolt there were 11 aftershocks that each had a magnitude greater than 6.0. The most significant damage was recorded within an area of 130,000 square kilometers. Many landslides and avalanches were produced due to more than four minutes of shaking. A tsunami, with waves up to 70 meters in height, was also created and took more than 130 human lives. Coastal marshlands and forests, that provided winter forage for animals like moose and migratory birds, were—together with other freshwater reservoirs—overcome and destroyed by salt water. Salmon spawning areas were affected by both saltwater and sediment from landslides. Many other fish and clams were killed as their habitats were disturbed. Avalanches in the mountains affected goats, sheep, deer and moose which were either killed or their habitat was wiped out. This earthquake—the largest ever recorded in the U.S. and the second largest recorded worldwide—permanently transformed the Alaskan landscape.

Contributed by Corrina Jones
Course: Modern Global Environmental History
Instructor: Dr. Wilko Graf von Hardenberg
University of Wisconsin–Madison, US