ABSTRACT: Holocene glaciation of Alaska (and Adjoining Yukon Territory, Canada)

CGRG Bibliography of Canadian Geomorphology
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Abstract

Holocene glacial fluctuations between Arctic, central interior, and southern maritime Alaska are broadly synchronous. This synchrony is evident from a review of work in 11 study areas with varying numbers of glaciers (3–100), glacier types (subpolar cirque, temperate valley, tidewater, surging), and dating methodologies. The pattern is temporally and spatially consistent with vegetation data, and generally with climatic deteriorations culminating in the Little Ice Age.Early Holocene glacial advances are confirmed for 7.6-5.8 lichen ka BP at 4 of 97 glaciers in the Brooks Range; advances also occurred by 5.85 and 5.7 ka BP at separate glacier tongues in the northern Alaska Range, at least by 6-5 ka BP in Lituya Bay, and possibly also in the Malaspina and Aleutian Islands areas. A sharp increase in glacier activity began by 4.4 ka BP in the Arctic and Glacier Bay areas, and by about 3 ka BP major glacier advances probably were initiated or well underway throughout Alaska. During Holocene glacial maxima, ice filled Glacier and Lituya Bays as well as fjords of Prince William Sound, and massive moraines buried forests in the northeastern St. Elias Mountains area. Minor recession is recorded directly or implied in most of Alaska about 2 ka BP or locally through the following millennium. Subsequently, distinct but locally weak advances occurred by about 1.2 ka BP in most areas, again followed by intervals of glacier recession.Most pervasive and ubiquitous were the Little Ice Age advances initiated about 700 BP. These generally culminated in two major advances between about 400 and 50 BP. In the Arctic, those of A.D. 1600 dominated those of the late 1800s; in the Gulf of Alaska, those of the middle 1700s or late 1800s dominated. Large scale, asynchronous advances and retreats of calving tidewater glaciers have been recorded during the twentieth century but most such movements are only indirectly related to climate.

Bibliography of Canadian Geomorphology