Seasonal Evolution of the Subglacial Hydrologic System Modified by Supraglacial Lake Drainage in Western Greenland
The impact of summer surface melt on Greenland Ice Sheet dynamics 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 inputs. Ho...
Published in: | Journal of Geophysical Research: Earth Surface |
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Online Access: | http://www.osti.gov/servlets/purl/1482953 https://www.osti.gov/biblio/1482953 https://doi.org/10.1029/2017JF004585 |
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ftosti:oai:osti.gov:1482953 2023-07-30T04:03:48+02:00 Seasonal Evolution of the Subglacial Hydrologic System Modified by Supraglacial Lake Drainage in Western Greenland Andrews, Lauren C. Hoffman, Matthew J. Neumann, Thomas A. Catania, Ginny A. Lüthi, Martin P. Hawley, Robert L. Schild, Kristin M. Ryser, Claudia Morriss, Blaine F. 2023-02-23 application/pdf http://www.osti.gov/servlets/purl/1482953 https://www.osti.gov/biblio/1482953 https://doi.org/10.1029/2017JF004585 unknown http://www.osti.gov/servlets/purl/1482953 https://www.osti.gov/biblio/1482953 https://doi.org/10.1029/2017JF004585 doi:10.1029/2017JF004585 58 GEOSCIENCES 2023 ftosti https://doi.org/10.1029/2017JF004585 2023-07-11T09:30:07Z The impact of summer surface melt on Greenland Ice Sheet dynamics 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 inputs. However, the behavior of the subglacial hydrologic system is complex and some characteristics are still poorly constrained. Here we investigate the coevolution of subglacial hydrology and ice motion in the Pâkitsoq region of western Greenland during the 2011 melt season. We analyze measurements from 11 Global Positioning System stations, from which we derive ice velocity, longitudinal strain rates, and basal uplift, alongside observations of surface ablation and supraglacial lake drainages. We observe ice acceleration after the onset of local surface melting, followed by gradual ice deceleration, consistent with increasing subglacial efficiency. In the study area, supraglacial lake drainages cooccur with a change in regional strain rate patterns and ice deceleration, suggesting that lake drainages contribute to rapid subglacial reorganization. At lower ice surface elevations (below ~900 m above sea level), ice motion is correlated with both total basal uplift and its rate of change, while at higher elevations (~900–1,100 m above sea level), ice motion correlated only with the basal uplift rate. This pattern suggests that continued cavity growth or subglacial sediment dynamics may be important in the apparent increase in subglacial drainage efficiency at higher elevations in the ablation zone. Furthermore, our results further suggest that transient subglacial behavior is important in the seasonal evolution of ice motion. Other/Unknown Material Greenland Ice Sheet SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) Greenland Journal of Geophysical Research: Earth Surface 123 6 1479 1496 |
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SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) |
op_collection_id |
ftosti |
language |
unknown |
topic |
58 GEOSCIENCES |
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58 GEOSCIENCES Andrews, Lauren C. Hoffman, Matthew J. Neumann, Thomas A. Catania, Ginny A. Lüthi, Martin P. Hawley, Robert L. Schild, Kristin M. Ryser, Claudia Morriss, Blaine F. Seasonal Evolution of the Subglacial Hydrologic System Modified by Supraglacial Lake Drainage in Western Greenland |
topic_facet |
58 GEOSCIENCES |
description |
The impact of summer surface melt on Greenland Ice Sheet dynamics 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 inputs. However, the behavior of the subglacial hydrologic system is complex and some characteristics are still poorly constrained. Here we investigate the coevolution of subglacial hydrology and ice motion in the Pâkitsoq region of western Greenland during the 2011 melt season. We analyze measurements from 11 Global Positioning System stations, from which we derive ice velocity, longitudinal strain rates, and basal uplift, alongside observations of surface ablation and supraglacial lake drainages. We observe ice acceleration after the onset of local surface melting, followed by gradual ice deceleration, consistent with increasing subglacial efficiency. In the study area, supraglacial lake drainages cooccur with a change in regional strain rate patterns and ice deceleration, suggesting that lake drainages contribute to rapid subglacial reorganization. At lower ice surface elevations (below ~900 m above sea level), ice motion is correlated with both total basal uplift and its rate of change, while at higher elevations (~900–1,100 m above sea level), ice motion correlated only with the basal uplift rate. This pattern suggests that continued cavity growth or subglacial sediment dynamics may be important in the apparent increase in subglacial drainage efficiency at higher elevations in the ablation zone. Furthermore, our results further suggest that transient subglacial behavior is important in the seasonal evolution of ice motion. |
author |
Andrews, Lauren C. Hoffman, Matthew J. Neumann, Thomas A. Catania, Ginny A. Lüthi, Martin P. Hawley, Robert L. Schild, Kristin M. Ryser, Claudia Morriss, Blaine F. |
author_facet |
Andrews, Lauren C. Hoffman, Matthew J. Neumann, Thomas A. Catania, Ginny A. Lüthi, Martin P. Hawley, Robert L. Schild, Kristin M. Ryser, Claudia Morriss, Blaine F. |
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 |
2023 |
url |
http://www.osti.gov/servlets/purl/1482953 https://www.osti.gov/biblio/1482953 https://doi.org/10.1029/2017JF004585 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland Ice Sheet |
genre_facet |
Greenland Ice Sheet |
op_relation |
http://www.osti.gov/servlets/purl/1482953 https://www.osti.gov/biblio/1482953 https://doi.org/10.1029/2017JF004585 doi:10.1029/2017JF004585 |
op_doi |
https://doi.org/10.1029/2017JF004585 |
container_title |
Journal of Geophysical Research: Earth Surface |
container_volume |
123 |
container_issue |
6 |
container_start_page |
1479 |
op_container_end_page |
1496 |
_version_ |
1772814913005158400 |