Do you live where the ground can subside?

About 55,000 square miles of Alaska subsided as much as 8 feet during the 1964 Alaskan earthquake, submerging low-lying parts of Portage, Whittier, Homer, Seldovia, and Kodiak. Although no one was killed from this process in the 1964 quake, regional subsidence can intensify the effects of tsunamis as well as render your property useless if it is submerged. Subsidence that will affect Alaskans is limited to coastal areas of southern Alaska and is caused by regional warping of the Earth's crust--a different process than local subsidence caused by landsliding.

Future large earthquakes will cause regional subsidence. It may not occur in the same area as the 1964 earthquake, but will probably affect areas of the Alaska Peninsula and the Aleutian Islands. Because the largest subsidence in the 1964 earthquake was about 8 feet, it would be wise to place structures more than 10 feet above sea level in coastal areas. Although a very large area was also uplifted in the 1964 quake--Cordova in particular was affected--uplift generally had a less harmful impact upon man than subsidence.