Filling and drainage of a subglacial lake beneath the Flade Isblink ice cap, northeast Greenland

Abstract. The generation, transport, storage and drainage of meltwater play important roles in the Greenland Ice Sheet (GrIS) subglacial system. Active lakes, common features Antarctica, have recently been detected beneath GrIS may impact ice sheet hydrology. Despite their potential importance, few repeat lake filling events identified Greenland. Here we examine surface elevation change a collapse basin at Flade Isblink cap, northeast Greenland, which formed due to sudden 2011. We estimate volume evolution using multi-temporal ArcticDEM data ICESat-2 altimetry acquired between 2012 2021. Our long-term observations show that was continuously filled by meltwater, with rising up 55 m during 2012–2021, 138.2 × 106 m3 transported into 2017. A second rapid event occurred late August 2019, induced an abrupt dynamic response. find 2019 released much less water than 2011 conclude multiple factors, such as stored bedrock relief, regulate episodic lake. By comparing production change, only ∼ 64 % descended bed, suggesting processes refreezing firn aquifer storage, need be further quantified.