The Knife Creek Glaciers of Katmai National Monument, Alaska

A group of previously unmapped glaciers on the slopes of Trident and Katmai Volcanoes, southwestern Alaska, was studied for information on the abnormal regimen produced by effects of the 1912 eruption of Mount Katmai. During the eruption an area of 5 square miles (13 km. 2 ) of the summit above regional snow line was destroyed, and the beheaded glaciers were buried under a blanket of pumice and ash. Field data are presented to indicate that the terminus of Fourth Glacier has been essentially stationary since the 1912 eruption. Upper portions of the glacier have thinned, exposing the rim of the caldera which 40 years ago was partly ringed with fringing ice cliffs. Permafrost has developed to within a few feet of the surface of the pumice mantle. Under prevailing climatic conditions Fourth Glacier may be preserved in its present static condition for an indefinite period.