Widespread Moulin Formation During Supraglacial Lake Drainages in Greenland
Moulins permit access of surface meltwater to the glacier bed, causing basal lubrication and ice speedup in the ablation zone of western Greenland during summer. Despite the substantial impact of moulins on ice dynamics, the conditions under which they form are poorly understood. We assimilate a tim...
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ftnasantrs:oai:casi.ntrs.nasa.gov:20180000574 2023-05-15T16:21:17+02:00 Widespread Moulin Formation During Supraglacial Lake Drainages in Greenland Andrews, Lauren C. Neumann, Thomas A. Hoffman, Matthew J. Johnson, Jesse Perego, Mauro Price, Stephen F. Catania, Ginny Luethi, Martin Unclassified, Unlimited, Publicly available January 17, 2018 application/pdf http://hdl.handle.net/2060/20180000574 unknown Document ID: 20180000574 http://hdl.handle.net/2060/20180000574 Copyright, Use by or on behalf of the U.S. Government permitted CASI Geophysics GSFC-E-DAA-TN50798 Geophysical Research Letters (ISSN 0094-8276) (e-ISSN 1944-8007); 45; 2; 778-788 2018 ftnasantrs 2019-07-20T23:21:04Z Moulins permit access of surface meltwater to the glacier bed, causing basal lubrication and ice speedup in the ablation zone of western Greenland during summer. Despite the substantial impact of moulins on ice dynamics, the conditions under which they form are poorly understood. We assimilate a time-series of ice surface velocity from a network of eleven Global Positioning System receivers into an ice sheet model to estimate ice sheet stresses during winter, spring, and summer in an approx. 30 x 10 km region. Surface-parallel von Mises stress increases slightly during spring speedup and early summer, sufficient to allow formation of 16% of moulins mapped in the study area. In contrast, 63% of moulins experience stresses over the tensile strength of ice during a short (hours) supraglacial lake drainage event. Lake drainages appear to control moulin density, which is itself a control on subglacial drainage efficiency and summer ice velocities. Other/Unknown Material glacier Greenland Ice Sheet NASA Technical Reports Server (NTRS) Greenland |
institution |
Open Polar |
collection |
NASA Technical Reports Server (NTRS) |
op_collection_id |
ftnasantrs |
language |
unknown |
topic |
Geophysics |
spellingShingle |
Geophysics Andrews, Lauren C. Neumann, Thomas A. Hoffman, Matthew J. Johnson, Jesse Perego, Mauro Price, Stephen F. Catania, Ginny Luethi, Martin Widespread Moulin Formation During Supraglacial Lake Drainages in Greenland |
topic_facet |
Geophysics |
description |
Moulins permit access of surface meltwater to the glacier bed, causing basal lubrication and ice speedup in the ablation zone of western Greenland during summer. Despite the substantial impact of moulins on ice dynamics, the conditions under which they form are poorly understood. We assimilate a time-series of ice surface velocity from a network of eleven Global Positioning System receivers into an ice sheet model to estimate ice sheet stresses during winter, spring, and summer in an approx. 30 x 10 km region. Surface-parallel von Mises stress increases slightly during spring speedup and early summer, sufficient to allow formation of 16% of moulins mapped in the study area. In contrast, 63% of moulins experience stresses over the tensile strength of ice during a short (hours) supraglacial lake drainage event. Lake drainages appear to control moulin density, which is itself a control on subglacial drainage efficiency and summer ice velocities. |
format |
Other/Unknown Material |
author |
Andrews, Lauren C. Neumann, Thomas A. Hoffman, Matthew J. Johnson, Jesse Perego, Mauro Price, Stephen F. Catania, Ginny Luethi, Martin |
author_facet |
Andrews, Lauren C. Neumann, Thomas A. Hoffman, Matthew J. Johnson, Jesse Perego, Mauro Price, Stephen F. Catania, Ginny Luethi, Martin |
author_sort |
Andrews, Lauren C. |
title |
Widespread Moulin Formation During Supraglacial Lake Drainages in Greenland |
title_short |
Widespread Moulin Formation During Supraglacial Lake Drainages in Greenland |
title_full |
Widespread Moulin Formation During Supraglacial Lake Drainages in Greenland |
title_fullStr |
Widespread Moulin Formation During Supraglacial Lake Drainages in Greenland |
title_full_unstemmed |
Widespread Moulin Formation During Supraglacial Lake Drainages in Greenland |
title_sort |
widespread moulin formation during supraglacial lake drainages in greenland |
publishDate |
2018 |
url |
http://hdl.handle.net/2060/20180000574 |
op_coverage |
Unclassified, Unlimited, Publicly available |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
glacier Greenland Ice Sheet |
genre_facet |
glacier Greenland Ice Sheet |
op_source |
CASI |
op_relation |
Document ID: 20180000574 http://hdl.handle.net/2060/20180000574 |
op_rights |
Copyright, Use by or on behalf of the U.S. Government permitted |
_version_ |
1766009296190963712 |