Abstract

Glaciers drain ice sheets by transporting ice from the interior to the coast where ice is discharged into the sea as icebergs. In Greenland, glaciers are flowing faster, posing a global risk of accelerated sea level rise. In this talk I report outcomes from the interdisciplinary RESPONDER project (www.erc-responder.eu), which is investigating hydrological networks and flow of the Greenland ice sheet. Using GPS -assisted drones with high accuracy, the team tracked meltwater pathways and found surface water to descend rapidly to the bed when supraglacial lakes are intercepted by extensional fractures forming along pre-existing structural weaknesses. We used a hot-water drill to gain access to the bed at specific targets, which included the shore of a rapidly draining lake, and the drained lake floor where a hydrological connection supplied a significant, but varying amount of surface water directly to the basal drainage system. With sensors deployed at the bed and within the ice, we observed the basal conditions that drive fast glacier flow.