TY - JOUR
T1 - Controls on the basal water pressure in subglacial channels near the margin of the Greenland ice sheet
AU - Ahlstrøm, Andreas P.
AU - Mohr, Johan J.
AU - Reeh, Niels
AU - Christensen, Erik Lintz
AU - Hooke, Roger Le B.
PY - 2005
Y1 - 2005
N2 - 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.
AB - 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.
KW - Greenland ice sheet
KW - basal water pressure
KW - subglacial drainage
UR - http://www.scopus.com/inward/record.url?scp=32644468378&partnerID=8YFLogxK
U2 - 10.3189/172756505781829214
DO - 10.3189/172756505781829214
M3 - Article
AN - SCOPUS:32644468378
SN - 0022-1430
VL - 51
SP - 443
EP - 450
JO - Journal of Glaciology
JF - Journal of Glaciology
IS - 174
ER -
