Abstract. Lakes in contact with glacier margins can impact glacier
evolution as well as the downstream biophysical systems, flood hazard, and
water resources. Recent work suggests positive feedbacks between glacier
wastage and ice-marginal lake evolution, although precise physical controls
are not well understood. Here, we quantify ice-marginal lake area change in
understudied northwestern North America from 1984–2018 and investigate
climatic, topographic, and glaciological influences on lake area change. We
delineate time series of sampled lake perimeters (n=107 lakes) and find
that regional lake area has increased 58 % in aggregate, with individual
proglacial lakes growing by 1.28 km2 (125 %) and ice-dammed lakes
shrinking by 0.04 km2 (−15 %) on average. A statistical
investigation of climate reanalysis data suggests that changes in summer
temperature and winter precipitation exert minimal direct influence on lake
area change. Utilizing existing datasets of observed and modeled glacial
characteristics, we find that large, wide glaciers with thick lake-adjacent
ice are associated with the fastest rate of lake area change, particularly
where they have been undergoing rapid mass loss in recent times. We observe a
dichotomy in which large, low-elevation coastal proglacial lakes have
changed most in absolute terms, while small, interior lakes at high
elevation have changed most in relative terms. Generally, the fastest-changing
lakes have not experienced the most dramatic temperature or precipitation
change, nor are they associated with the highest rates of glacier mass loss.
Our work suggests that, while climatic and glaciological factors must play
some role in determining lake area change, the influence of a lake's
specific geometry and topographic setting overrides these external controls.
Supplementary material to "Topography exerts primary control on the rate of Gulf of Alaska
ice-marginal lake area change over the Landsat record"
