Seasonal Evolution of the Subglacial Hydrologic System Modified by Supraglacial Lake Drainage in Western Greenland
The impact of summer surface melt on the dynamics of the Greenland Ice Sheet is modulated by the state of the subglacial hydrologic system. Studies of ice motion indicate that efficiency of the subglacial system increases over the melt season, decreasing the sensitivity of ice motion to surface melt...
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ftnasantrs:oai:casi.ntrs.nasa.gov:20180002930 2023-05-15T16:27:17+02:00 Seasonal Evolution of the Subglacial Hydrologic System Modified by Supraglacial Lake Drainage in Western Greenland Andrews, Lauren C. Hoffman, Matthew J. Morriss, Blaine F. Neumann, Thomas A. Hawley, Robert, L. Catania, Ginny A. Schild, Kristin M. Ryser, Claudia Luthi, Martin P. Unclassified, Unlimited, Publicly available May 24, 2018 application/pdf http://hdl.handle.net/2060/20180002930 unknown Document ID: 20180002930 http://hdl.handle.net/2060/20180002930 Copyright, Use by or on behalf of the U.S. Government permitted CASI Earth Resources and Remote Sensing GSFC-E-DAA-TN55785 Journal of Geophysical Research: Earth Surface (ISSN 2169-9011) (e-ISSN 2169-9011); 123; 6; 1479-1496 2018 ftnasantrs 2019-09-28T22:47:10Z The impact of summer surface melt on the dynamics of the Greenland Ice Sheet is modulated by the state of the subglacial hydrologic system. Studies of ice motion indicate that efficiency of the subglacial system increases over the melt season, decreasing the sensitivity of ice motion to surface melt. However, these inferences are based on limited indirect observations of the subglacial hydrologic system that leave many factors poorly constrained, particularly the presence and stability of subglacial channels. Here we use observations from 11 GPS stations, from which we derive ice velocity, longitudinal strain rates, and basal uplift, alongside observations of surface ablation and supraglacial lake drainage events, to explore the coevolution of ice motion and the subglacial hydrologic system in the Pakitsoq region of western Greenland during the 2011 melt season. We observe ice acceleration after the onset of local surface melting, followed by gradual ice deceleration, consistent with the pattern expected from increased subglacial drainage efficiency. Supraglacial lake drainages appear to precipitate ice deceleration and increased basal traction, suggesting that lake drainages effectively reorganize the local subglacial hydrologic system into a more efficient state that persists through the remainder of the melt season. At high elevations, ice velocity and inferred basal uplift suggest that continued cavity growth or sediment behavior, not subglacial channelization, drive the apparent increase in subglacial efficiency. Our results further indicate that these transient perturbations are critical in the seasonal evolution of ice motion. Other/Unknown Material Greenland Ice Sheet NASA Technical Reports Server (NTRS) Greenland |
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Open Polar |
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NASA Technical Reports Server (NTRS) |
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ftnasantrs |
language |
unknown |
topic |
Earth Resources and Remote Sensing |
spellingShingle |
Earth Resources and Remote Sensing Andrews, Lauren C. Hoffman, Matthew J. Morriss, Blaine F. Neumann, Thomas A. Hawley, Robert, L. Catania, Ginny A. Schild, Kristin M. Ryser, Claudia Luthi, Martin P. Seasonal Evolution of the Subglacial Hydrologic System Modified by Supraglacial Lake Drainage in Western Greenland |
topic_facet |
Earth Resources and Remote Sensing |
description |
The impact of summer surface melt on the dynamics of the Greenland Ice Sheet is modulated by the state of the subglacial hydrologic system. Studies of ice motion indicate that efficiency of the subglacial system increases over the melt season, decreasing the sensitivity of ice motion to surface melt. However, these inferences are based on limited indirect observations of the subglacial hydrologic system that leave many factors poorly constrained, particularly the presence and stability of subglacial channels. Here we use observations from 11 GPS stations, from which we derive ice velocity, longitudinal strain rates, and basal uplift, alongside observations of surface ablation and supraglacial lake drainage events, to explore the coevolution of ice motion and the subglacial hydrologic system in the Pakitsoq region of western Greenland during the 2011 melt season. We observe ice acceleration after the onset of local surface melting, followed by gradual ice deceleration, consistent with the pattern expected from increased subglacial drainage efficiency. Supraglacial lake drainages appear to precipitate ice deceleration and increased basal traction, suggesting that lake drainages effectively reorganize the local subglacial hydrologic system into a more efficient state that persists through the remainder of the melt season. At high elevations, ice velocity and inferred basal uplift suggest that continued cavity growth or sediment behavior, not subglacial channelization, drive the apparent increase in subglacial efficiency. Our results further indicate that these transient perturbations are critical in the seasonal evolution of ice motion. |
format |
Other/Unknown Material |
author |
Andrews, Lauren C. Hoffman, Matthew J. Morriss, Blaine F. Neumann, Thomas A. Hawley, Robert, L. Catania, Ginny A. Schild, Kristin M. Ryser, Claudia Luthi, Martin P. |
author_facet |
Andrews, Lauren C. Hoffman, Matthew J. Morriss, Blaine F. Neumann, Thomas A. Hawley, Robert, L. Catania, Ginny A. Schild, Kristin M. Ryser, Claudia Luthi, Martin P. |
author_sort |
Andrews, Lauren C. |
title |
Seasonal Evolution of the Subglacial Hydrologic System Modified by Supraglacial Lake Drainage in Western Greenland |
title_short |
Seasonal Evolution of the Subglacial Hydrologic System Modified by Supraglacial Lake Drainage in Western Greenland |
title_full |
Seasonal Evolution of the Subglacial Hydrologic System Modified by Supraglacial Lake Drainage in Western Greenland |
title_fullStr |
Seasonal Evolution of the Subglacial Hydrologic System Modified by Supraglacial Lake Drainage in Western Greenland |
title_full_unstemmed |
Seasonal Evolution of the Subglacial Hydrologic System Modified by Supraglacial Lake Drainage in Western Greenland |
title_sort |
seasonal evolution of the subglacial hydrologic system modified by supraglacial lake drainage in western greenland |
publishDate |
2018 |
url |
http://hdl.handle.net/2060/20180002930 |
op_coverage |
Unclassified, Unlimited, Publicly available |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland Ice Sheet |
genre_facet |
Greenland Ice Sheet |
op_source |
CASI |
op_relation |
Document ID: 20180002930 http://hdl.handle.net/2060/20180002930 |
op_rights |
Copyright, Use by or on behalf of the U.S. Government permitted |
_version_ |
1766016410093355008 |