On 27 March 1964 at 5:36pm a 9.2 magnitude earthquake hit Prince William Sound. 115 Alaskans were killed from the quake and the tsunamis that followed. 16 people also died in Oregon and California.
The Good Friday Earthquake was a megathrust quake that shook Alaska for over 4 minutes straight. It released 50 times as much energy as the 1906 San Francisco earthquake; fishing boats in Lousiana sank, well water in South Africa rose, Sheep Creek in Anchorage stopped flowing for 18 hours, and the intervals of eruptions of Old Faithful Geyser in Yellowstone shortened. It is the largest earthquake to hit North America and the second largest to ever be recorded. There were thousands of aftershocks in the weeks following. The next day alone had 11 shocks registering over 6.0.
100,000 square miles of Alaska twisted, broke, dropped and rose. The coastal community of Portage dropped ten feet causing flooding from Turnagain Arm. The town of Seward moved 47 feet south, Cordova 46 feet southeast, and parts of Montague Island rose 30 feet.
The tsunamis caused the most damage and loss of life. The waves that hit Shoup Bay reached 100 feet above sea level, and 60 feet above sea level at Kodiak. Some remote areas show evidence of waves 220 feet above sea level.