Brief communication: Subglacial lake drainage beneath Isunguata Sermia, West Greenland: Geomorphic and ice dynamic effects

Abstract

We report three active subglacial lakes within 2km of the lateral margin of Isunguata Sermia, West Greenland, identified by differencing time-stamped ArcticDEM strips. Each lake underwent one drainage-refill event between 2009 and 2017, with two lakes draining in <1 month in August 2014 and August 2015. The 2015 drainage caused a ∼1-month down-glacier slowdown in ice flow and flooded the foreland, aggrading the proglacial channel by 8m. The proglacial flooding confirms the ice-surface elevation anomalies as subglacial water bodies and demonstrates how their drainage can significantly modify proglacial environments. These subglacial lakes offer accessible targets for geophysical investigations and exploration.