Controls on the basal water pressure in subglacial channels near the margin of the Greenland ice sheet

Andreas P. Ahlstrøm, Johan J. Mohr, Niels Reeh, Erik Lintz Christensen, Roger Le B. Hooke

Publikation: Bidrag til tidsskriftArtikelForskningpeer review

11 Citationer (Scopus)


Assuming a channelized drainage system in steady state, we investigate the influence of enhanced surface melting on the water pressure in subglacial channels, compared to that of changes in conduit geometry, ice rheology and catchment variations. The analysis is carried out for a specific part of the western Greenland ice-sheet margin between 66° N and 66° 30′ N using new high-resolution digital elevation models of the subglacial topography and the ice-sheet surface, based on an airborne ice-penetrating radar survey in 2003 and satellite repeat-track interferometric synthetic aperture radar analysis of European Remote-sensing Satellite 1 and 2 (ERS-1/-2) imagery, respectively. The water pressure is calculated up-glacier along a likely subglacial channel at distances of 1, 5 and 9 km from the outlet at the ice margin, using a modified version of Röthlisberger's equation. Our results show that for the margin of the western Greenland ice sheet, the water pressure in subglacial channels is not sensitive to realistic variations in catchment size and mean surface water input compared to small changes in conduit geometry and ice rheology.

Sider (fra-til)443-450
Antal sider8
TidsskriftJournal of Glaciology
Udgave nummer174
StatusUdgivet - 2005
Udgivet eksterntJa


  • Programområde 5: Natur og klima


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