On "Good Friday" March 27, 1964, at 5:36 PM, a M9.2 quake struck southern Alaska. 

 

Measuring X-XI on the Modified Mercali scale, the epicenter was about 80 miles east-southeast of Anchorage on a "megathrust" fault in a subduction zone. 

 

The fault rupture ran over 420 miles from Prince William Sound to just below Kodiak Island.  Changes in earth levels due to uplift or subsidence ranged as much as 42 - 50 feet in various places. 

 

Some people experienced shaking for over nine minutes. 

 

A devastating tsunami followed, impacting Northern California coastlines and other areas of the northern Pacific region of the United States.