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Title: Gulf of Alaska ice-marginal lake area change over the Landsat record and potential physical controls
Abstract. Lakes in contact with glacier margins can impact glacierevolution as well as the downstream biophysical systems, flood hazard, andwater resources. Recent work suggests positive feedbacks between glacierwastage and ice-marginal lake evolution, although precise physical controlsare not well understood. Here, we quantify ice-marginal lake area change inunderstudied northwestern North America from 1984–2018 and investigateclimatic, topographic, and glaciological influences on lake area change. Wedelineate time series of sampled lake perimeters (n=107 lakes) and findthat regional lake area has increased 58 % in aggregate, with individualproglacial lakes growing by 1.28 km2 (125 %) and ice-dammed lakesshrinking by 0.04 km2 (−15 %) on average. A statisticalinvestigation of climate reanalysis data suggests that changes in summertemperature and winter precipitation exert minimal direct influence on lakearea change. Utilizing existing datasets of observed and modeled glacialcharacteristics, we find that large, wide glaciers with thick lake-adjacentice are associated with the fastest rate of lake area change, particularlywhere they have been undergoing rapid mass loss in recent times. We observe adichotomy in which large, low-elevation coastal proglacial lakes havechanged most in absolute terms, while small, interior lakes at highelevation have changed most in relative terms. Generally, the fastest-changinglakes have not experienced the most dramatic temperature or precipitationchange, nor are they associated with the highest rates of glacier mass loss.Our work suggests that, while climatic and glaciological factors must playsome role in determining lake area change, the influence of a lake'sspecific geometry and topographic setting overrides these external controls.  more » « less
Award ID(s):
Author(s) / Creator(s):
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Date Published:
Journal Name:
The Cryosphere
Page Range / eLocation ID:
3255 to 3278
Medium: X
Sponsoring Org:
National Science Foundation
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