Subglacial water drainage, storage, and piracy beneath the Greenland ice sheet

Authors Organisations
Type Article
Original languageEnglish
Pages (from-to)7606-7614
Number of pages9
JournalGeophysical Research Letters
Volume42
Issue number18
Early online date30 Sep 2015
DOI
Publication statusPublished - 17 Oct 2015
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Abstract

Meltwater drainage across the surface of the Greenland ice sheet (GrIS) is well constrained by measurements and modeling, yet despite its critical role, knowledge of its transit through the subglacial environment remains limited. Here we present a subglacial hydrological analysis of a land-terminating sector of the GrIS at unprecedented resolution that predicts the routing of surface-derived meltwater once it has entered the basal drainage system. Our analysis indicates the probable existence of small subglacial lakes that remain undetectable by methods using surface elevation change or radar techniques. Furthermore, the analysis suggests transient behavior with rapid switching of subglacial drainage between competing catchments driven by seasonal changes in the basal water pressure. Our findings provide a cautionary note that should be considered in studies that attempt to relate and infer future response from surface temperature, melt, and runoff from point measurements and/or modeling with measurements of proglacial discharge and ice dynamics.

Keywords

  • Greenland ice sheet, ice sheet hydrology, ice sheet dynamics