Active subglacial lakes in the Canadian Arctic identified by multi-annual ice elevation changes

Abstract. Subglacial lakes influence glacier hydrology, dynamics, and mass balance; however, they are poorly documented outside the polar ice sheets. Here we use high-resolution digital elevation models during 2011–2021 and regression analysis to characterize subglacial lakes. We identified 37 subglacial lakes across the Canadian Arctic, 35 of which are newly identified. These lakes have an area of 0.3–48.5 km2 and can change surface elevation by 10–150 m, corresponding to a water volume of 0.003–4.5 km3. We classify these subglacial lakes into three types: (1) classic subglacial lakes, (2) terminal subglacial lakes at places where two glacier termini converge and coalesce, and (3) partial subglacial lakes with an area of open water at the ice margin. Types 2 and 3 are newly introduced in this study, there are 11 and 15 lakes classified as these two types, respectively. Lake activities negatively correlate with regional mass balance (r=-0.69, p-value =0.039), implying a need for fine-scale monitoring in the era of increased glacier loss.