1964 Good Friday
Great Alaskan Earthquake:
UPLIFT and SUBSIDENCE

After the Great Alaskan Earthquake of 1964:

• An area 520,000 square kilometers (200,773 square miles) was affected by uplift or subsidence in total.(6)
• The vertical deformation area in Alaska totaled 250,000 square kilometers (100,000 square miles)(2)
• Zone of subsidence totaled 285,000 square kilometers, and included areas of Prince William Sound, north and west Chugach Mountains, west Kenai Peninsula, and Kodiak Island.(6)
• 180,000 square kilometers (70,000square miles) of Alaska had subsided over one meter. Much of this land is along the coast, and now floods at high tide.(4)
• Parts of the Gulf of Alaska were uplifted 11 meters (36 feet), exposing former tidelands of Montague Island in Prince William Sound, Alaska.(4)
• The rise was estimated to come in two thrusts of about 5 meters (16 feet) each.(2)
• Vertical displacement recorded was 11.5 meters (38 feet) of uplift in some areas, while others subsided 2.3 meters (7.5 feet) relative to sea level.(6)
• The hinge line between these two areas extended from near the epicenter in Prince William Sound to the Southeast coast of Kodiak Island.(2)
  

  Montague Island, Alaska

  Off the southwest end of Montague Island, absolute vertical displacement was 13 to 15 meters (42.5 feet to 49 feet)(6)

  The extreme southern coast of Alaska, which includes Kodiak Island, Sitkalidak Island, and Sitkinak Island were all uplifted.(6)

  The end result was that the Pacific plate moved under the North American Plate about 9 meters (30 feet) on average.(2)

  Latouche Island, Alaska

  Moved 18 meters (59 feet) to the southeast.(2)

  Portage, Alaska

  This area down dropped 3 meters (8 feet).(2)
  

  Learn more about the 1964 Good Friday Great Alaskan Earthquake

  
  

  1964 Good Friday Great Alaskan Earthquake Overview	The Earthquake That Started It All
  Giant Waves Caused Fifteen Deaths	A Huge Piece of Land Walked Into The Sea
  It All Happened Here Before (And Probably Will Again)	What The Words All Mean (Vocabulary Definitions)

  
  

  Other sites of interest:

  Windows to Arizona Geology

  United States Geological Survey Report on the Alaskan quake.
  

  Credits

  With many thanks to the following sources:
  
  Macklin, T. for photos by his brother.
  
  1) Bolt, B., 1993, Earthquakes. W.H.Freeman and Company.
  
  2) Christensen, D. http://www.aeic.alaska.edu/Seis/64quake/quake_description.html
  3) Lutgens, F. and Tarbeck, E., 1995, Essentials in Geology. Prentice Hall.
  
  4) Pipkin, B. and Trent, D., 1997, Geology and the Environment. West/Wadsworth.
  
  5) Sokolowski, T. http://wcatwc.gov/64quake.htm
  
  6) United States Geological Survey. http://wwwneic.cr.usgs.gov/neis/eqlists/USA/1964_03_28.html
  

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  Page by Nievita Bueno Hartness
  Last Updated 12/06/2001
  
  
  E-mail me at: nhartnes@geo.arizona.edu