Morphometry of glacial lakes formed in front of glaciers C-93 and C-79

In formerly glaciated permafrost regions, extensive areas are still underlain by a considerable amount of glacier ice buried by glacigenic sediments. Although the extent and volume of undisturbed relict glacier ice are unknown, these ice bodies are predicted to melt with climate warming but their impact on landscape evolution remains poorly studied. The spatial distribution of buried glacier ice can play a significant role in reshaping periglacial landscapes, in particular thermokarst aquatic systems. This study focuses on lake initiation and development in response to the melting of buried glacier ice on Bylot Island, Nunavut. As part of this study, we were interested in the formation of glacial lakes in the proglacial environments of glaciers C-93 and C-79. It provides provide the best modern analogue for examining the formation of lakes in environments underlain by buried glacier ice. We used contemporary high-resolution GeoEye satellite imagery (2010, pixel = 0.5 m), WorldView-1 (2010, pixel = 0.5 m) and ArcticDEM data (pixel = 2 m) to map lakes. For each lake, we calculated the area, perimeter, elongation ratio (AR; long axis/short axis), and shoreline development or DL from the digitized shoreline polygons. The shoreline development ratio (DL) is a standard measure of the complexity of the shoreline, which is the ratio of the length of the shoreline of a lake (i.e. perimeter) to the circumference of a circle of area equal to that of the lake (Equation 1; Hutchinson, 1957). DL for a perfect circle is 1.0, and its value increases (>>1) as the shape of the lake surface deviates from that of a circle, indicating the shoreline is more dendritic or irregular. Equation 1: DL = Perimeter / (2*√(Area*π))

Community of Mittimatalik, Parks Canada, PCSP, ArcticNet

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Version 1.0 (2010-2010) - Updated August 22, 2022