Volume, evolution, and sedimentation of future glacier lakes in Switzerland over the 21st century

[摘要] Ongoing climate change and associated glacier retreat iscausing rapid environmental change, including shifts in high-alpinelandscapes. Glacier lakes, which can form in topographical depressions leftbehind by glacier retreat, are prominent features within such landscapes.Whilst model-based estimates for the number and area of future glacier lakesexist for various mountain regions across the world, the exact morphologyand temporal evolution remain largely unassessed. Here, we leverage arecently released, measurement-based estimate for the subglacial topographyof all glaciers in the Swiss Alps to provide an estimate about the number,size, time of emergence, and sediment infill of future glacier lakes.The topographical information is based on 2450 km of measured ice thicknessprofiles, whilst the temporal evolution of glaciers is obtained from aglacier evolution model forced with an ensemble of climate projections. Weestimate that up to 683 potential lakes with an area > 5000  m 2 and a depth > 5  m could emerge across the Swiss Alps ifglaciers were to disappear completely, with the potential to hold a totalwater volume of up to 1.16 [1.05, 1.32] km 3 (numbers and 95 %confidence interval). For a middle-of-the-road climate scenario, we estimatethat about 10 % (0.12 [0.04, 0.18] km 3 ) and 48 % (0.56 [0.26, 0.67] km 3 ) of this volume could be realized by 2050 and 2100, respectively.In a first-order assessment, we also estimate that ca. 45 % of the newlyemerging glacier lakes (260 out of 570) will be transient features, i.e.will disappear again before the end of the century owing to refilling withsediments released by glacial erosion and proglacial sediment transport.

[学科分类] 土壤学