Decades of supraglacial hydrological network evolution on Ellesmere Island’s glaciers

Over the past two decades, the Canadian Arctic Archipelago has undergone significant glacier mass loss, driven primarily by surface melt. This study presents a detailed analysis of supraglacial drainage evolution along Ellesmere Island’s ~830 km latitudinal extent using satellite imagery, historical aerial photographs, and DEMs from 1959 to 2020. Analysis of five glaciers shows that drainage density (Dd) has increased over time, driven by the expansion of perennial rivers, especially at higher elevations. Far northern glaciers exhibit stable, well-developed drainage systems, while southern glaciers show a relatively greater increase in canyon development since 1959. Cold surface ice in the north supports higher Dd, while southern glaciers with extensive sinks (moulins and large crevasses) exhibit stronger surface-to-bed connectivity. Despite increased channelization, sinuosity changes remain statistically insignificant, reflecting dynamic canyon behavior governed by surface slope and meltwater discharge. Results align with modeled increases in melt, especially on southern glaciers where supraglacial systems have expanded most rapidly. Continued Equilibrium Line Altitude rise under future warming is expected to intensify melt and result in an expansion of supraglacial drainage systems up-glacier, particularly for glaciers with large amounts of ice at mid-elevation.