CGRG Bibliography of Canadian Geomorphology
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Author : Church, A.; and Clague, J.J.
Date : 2009.
Title : Recent deglacierization of the Upper Wheaton River Watershed, Yukon Territory .
Publication : CANQUA–CGRG Biennial Meeting. May 3-8, 2009. Simon Fraser University, Burnaby Campus, Burnaby, British Columbia.
Issue : Programme and Abstracts Volume.
Page(s) : 56.
Abstract
We document rapid loss of glacier ice in the Wheaton River watershed which contains the northeastern-most glaciers within the Coast Mountains. Our research involves the study of the Wheaton glacier, the largest of the glaciers in the Wheaton River watershed. Since the Little Ice Age, the Wheaton glacier has lost 50% of its area and 58 to 63% of its volume. Thinning and retreat have accelerated in the past 40 years and the glacier is now so thin and short that it may disappear during this century. This loss was quantified through the analysis of sequential aerial photography and bivariate scaling analysis. Observations in the climate record from 1907 to 2005 have shown an increase in mean atmospheric temperature, as well as an increase in average winter snowfall. Despite increasing winter snowfall, changes in temperature continue to be the main cause of the persistent negative mass balance of the Wheaton glacier. Warming and glacier recession are altering sediment delivery in the upper Wheaton River watershed. A pulse of sediment is moving downstream from the Wheaton Glacier forefield and affecting the fan at the mouth of the valley. Large, out-of-channel debris flows are spilling across the fan, aggrading and shifting the stream channel. Evidence from cores and ground-penetrating radar surveys suggest that debris flows have dominated sedimentation on the fan during the last half of the Holocene, coincident with Neoglacial advances culminating in the Little Ice Age and the period of rapid glacier retreat following the Little Ice Age. Triggers identified for some of the debris flows include the draining of a proglacial lake, a rockfall possibly caused by glacial de-buttressing, increased sediment availability associated with glacier retreat; and rock glacier activity.
Bibliography of Canadian Geomorphology