The Great Alaska Earthquake of 1964: The Day the Ground Moved for Four Minutes

On Good Friday, March 27, 1964, the most powerful earthquake ever recorded in North America struck southern Alaska. The ground shook for about four and a half minutes. Neighborhoods in Anchorage slid toward the sea, waterfronts in Valdez and Seward collapsed, and a tsunami crossed the Pacific. Afterwards, geologists measuring barnacle lines and sunken forests found the clues that helped confirm plate tectonics. Chapters 0:00 Good Friday, 1964 0:58 Where it happened 1:45 The fault beneath Alaska 2:38 Anchorage: the clay gives way 4:26 The water: Valdez, Seward and Prince William Sound 5:32 The tsunami crosses the Pacific 6:28 The toll and the recovery 6:56 Land that sank and land that rose 8:30 How Alaska helped prove plate tectonics 9:19 Warnings and lessons 10:19 Remembering 1964 Photo credits: U.S. Geological Survey (including photographers A. Grantz, W.R. Hansen and G. Plafker), U.S. Army, U.S. Army Corps of Engineers (via National Archives at Seattle), U.S. Navy, U.S. Air Force, U.S. Fish and Wildlife Service, U.S. Coast & Geodetic Survey / NOAA Photo Library, Ellin Beltz (public domain). Maps use Natural Earth data. Maps and diagrams are simplified illustrations. Sources: USGS Earthquake Hazards Program, "M9.2 Alaska Earthquake and Tsunami of March 27, 1964"; Plafker, G. (1965), "Tectonic deformation associated with the 1964 Alaska earthquake," Science; NOAA National Tsunami Warning Center history. #Alaska #Earthquake #History