Permafrost and related engineering problems in Alaska

Abstract

Permafrost, or perennially frozen ground, is a widespread natural phenomenon. It underlies approxinately 20 percent of the land area of the world. The >ermaf rost region of Alaska, which includes 85 percent >f the State, is characterized by a variety of perma-'rost-related geomorphic features including patterned ground, pingos, thaw lakes, beaded drainage, thaw or thermokarst pits, and muck deposits. Known permafrost thickness ranges from about 1,300 feet near Barrow in northern Alaska to less than a foot at the southern margin of the permafrost region. The distribution of permafrost is controlled by climatic, geologic, hydrologic, topographic, and botanic factors.