Distribution and dynamics of Greenland subglacial lakes.
Where this comes from
- Record sourced from PubMed, PMID 31243282.
- Also identified by DOI 10.1038/s41467-019-10821-w and PMC identifier 6594964.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Few subglacial lakes have been identified beneath the Greenland Ice Sheet (GrIS) despite extensive documentation in Antarctica, where periodic release of water can impact ice flow. Here we present an ice-sheet-wide survey of Greenland subglacial lakes, identifying 54 candidates from airborne radio-echo sounding, and 2 lakes from ice-surface elevation changes. These range from 0.2-5.9 km in length, and are mostly distributed away from ice divides, beneath relatively slow-moving ice. Based on our results and previous observations, we suggest three zones of formation: stable lakes in northern and eastern regions above the Equilibrium Line Altitude (ELA) but away from the interior; hydrologically-active lakes near the ELA recharged by surface meltwater and; small, seasonally-active lakes below the ELA, which form over winter and drain during the melt season. These observations provide important constraints on the GrIS's basal thermal regime and help refine our understanding of the subglacial hydrological system.