Abstract
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.
Highlights
IntroductionThe development and evolution of ice-marginal lakes (both proglacial and ice-dammed lakes) may have implications for both upstream glacier systems and downstream fluvial environments (Baker et al, 2016; Otto, 2019; Tweed and Carrivick, 2015)
The development and evolution of ice-marginal lakes may have implications for both upstream glacier systems and downstream fluvial environments (Baker et al, 2016; Otto, 2019; Tweed and Carrivick, 2015)
The presence of icedammed lakes enables glacial outburst floods (GLOFs) that contribute to short-term changes in downstream geomorphologic and hydrologic dynamics and may pose a serious hazard to downstream communities (Carrivick and Tweed, 2016; Roberts et al, 2003; Tweed and Russell, 1999)
Summary
The development and evolution of ice-marginal lakes (both proglacial and ice-dammed lakes) may have implications for both upstream glacier systems and downstream fluvial environments (Baker et al, 2016; Otto, 2019; Tweed and Carrivick, 2015). Field et al.: Gulf of Alaska ice-marginal lake area change over the Landsat record ical controls on ice-marginal lake formation and evolution (Falatkova et al, 2019; Magnin et al, 2020). To address this knowledge gap, we investigate trends in ice-marginal lake area change across northwestern North America, a relatively unstudied region, over the satellite record and explore physical controls on observed behavior
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
