Controls on Water Storage and Drainage in Crevasses on the Greenland Ice Sheet

Surface crevasses on the Greenland Ice Sheet (GrIS) capture nearly half of seasonal runoff, yet their role in transferring meltwater to bed has received little attention relative that supraglacial lakes and moulins. Here, we present observations crevasse ponding investigate controls hydrological behavior at a fast-moving, marine-terminating sector GrIS. We map surface meltwater, crevasses, surface-parallel stress across ∼2,700 km2 region using satellite data contemporaneous uncrewed aerial vehicle (UAV) surveys. From 2017 2019 an average 26% crevassed area exhibited locations remained persistent between years despite rapid advection. find spatial distribution ponded does not relate previously proposed (elevation topography) or (von Mises thresholds), suggesting operation some other physical control(s). Ponded fields were preferentially located regions compressive mean stress, which interpret result from hydraulic isolation these systems. This contrasts with unponded fields, suggest are readily able transport into wider englacial network. UAV show can drain episodically rapidly, likely through hydrofracture. therefore propose regime influences spatially heterogeneous transfer ice sheets, consequences for processes, such as subglacial drainage heating via latent heat release by refreezing meltwater.