1964 Alaska great earthquake and tsunami — second most powerful earthquake to hit a region in recorded history
The 1964 Alaska earthquake was the most powerful ever recorded in North America and second most powerful worldwide, causing 139 deaths across multiple regions.
Key Facts
- Magnitude
- 9.2–9.3 (megathrust)
- Duration
- 4 minutes 38 seconds
- Death toll
- ~139 deaths
- Fault rupture length
- 600 miles
- Maximum fault displacement
- 60 ft
- Date
- March 27, 1964 (Good Friday)
By the Numbers
Location
Cause → Event → Consequence
Approximately 500 years of accumulated tectonic stress along a subduction zone in south-central Alaska built up along a megathrust fault. On March 27, 1964, this stress released catastrophically when roughly 600 miles of fault ruptured simultaneously, displacing the ground by up to 60 feet and generating one of the most energetic seismic events recorded in the modern era.
At 5:36 PM AKST on Good Friday, March 27, 1964, a magnitude 9.2–9.3 earthquake struck south-central Alaska, lasting four minutes and thirty-eight seconds. Ground fissures, soil liquefaction, landslides, and structural collapses devastated Anchorage and surrounding communities. Port Valdez experienced a massive underwater landslide killing 32 people, while the village of Chenega was destroyed by a 27-foot tsunami that killed 23 of its 68 residents.
The earthquake and resulting tsunamis killed about 139 people and caused widespread destruction across Alaska, with damage extending to British Columbia, Washington, Oregon, California, Hawaii, and Japan. Some coastal areas near Kodiak were permanently raised by 30 feet, while areas near Girdwood dropped 8 feet, necessitating major infrastructure reconstruction. The event prompted significant advances in earthquake engineering and tsunami warning systems.
Human Cost
Each dot represents approximately 10,000 deaths. Total estimated: 139 (earthquake)