Preliminary report on the reconnaissance engineering geology of the Yakutat area, Alaska, with emphasis on evaluation of earthquake and other geologic hazards

Yakutat, situated about 225 miles northwest of Juneau, Alaska, near the shores of the Gulf of Alaska, has a setting that calls for superlatives. Within the Yakutat region are some of the tallest mountains, some of the heaviest snowfalls, and the largest glacier in North America. Between the abrupt mountain front and the Gulf of Alaska lies a very gently sloping plain of outwash derived from repeated cycles of advance followed by melt and retreat of glaciers during the Quaternary Period. The latest melting probably took place 500 to 600 years ago. Yakutat is built upon the moderately steep moraine that is the product of melting of one of these glaciers. Near Yakutat, surficial deposits are as much as 700 feet thick and probably overlie siltstone, sandstone, and mudstone. The eight general categories of mapped surficial deposits include artificial fill, organic, eolian, beach, delta-estuarine, alluvial, and outwash deposits, and deposits of the outer Yakutat Bay moraine complex.