Sustained High Basal Motion of the Greenland Ice Sheet Revealed by Borehole Deformation
Ice deformation and basal motion characterize the dynamical behavior of the Greenland ice sheet (GrIS). We evaluate the contribution of basal motion from ice deformation measurements in boreholes drilled to the bed at two sites in the western marginal zone of the GrIS. We find a sustained high amoun...
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ftdartmouthcoll:oai:digitalcommons.dartmouth.edu:facoa-2756 2023-07-16T03:58:34+02:00 Sustained High Basal Motion of the Greenland Ice Sheet Revealed by Borehole Deformation Ryser, Claudia Lüthi, Martin P Andrews, Lauren C Hoffman, Matthew J Catania, Ginny A Hawley, Robert L 2014-04-21T07:00:00Z application/pdf https://digitalcommons.dartmouth.edu/facoa/1753 https://doi.org/10.3189/2014JoG13J196 https://digitalcommons.dartmouth.edu/context/facoa/article/2756/viewcontent/sustained_high_basal_motion_of_the_greenland_ice_sheet_revealed_by_borehole_deformation.pdf unknown Dartmouth Digital Commons https://digitalcommons.dartmouth.edu/facoa/1753 doi:10.3189/2014JoG13J196 https://digitalcommons.dartmouth.edu/context/facoa/article/2756/viewcontent/sustained_high_basal_motion_of_the_greenland_ice_sheet_revealed_by_borehole_deformation.pdf Dartmouth Scholarship polar region ice sheets seasonal variations borehole glacier bed basal ice deformation measurement rheology flow velocity modeling marginal ice zone Earth Sciences Glaciology Physical Sciences and Mathematics text 2014 ftdartmouthcoll https://doi.org/10.3189/2014JoG13J196 2023-06-28T10:43:30Z Ice deformation and basal motion characterize the dynamical behavior of the Greenland ice sheet (GrIS). We evaluate the contribution of basal motion from ice deformation measurements in boreholes drilled to the bed at two sites in the western marginal zone of the GrIS. We find a sustained high amount of basal motion contribution to surface velocity of 44–73% in winter, and up to 90% in summer. Measured ice deformation rates show an unexpected variation with depth that can be explained with the help of an ice-flow model as a consequence of stress transfer from slippery to sticky areas. This effect necessitates the use of high-order ice-flow models, not only in regions of fast-flowing ice streams but in all temperate-based areas of the GrIS. The agreement between modeled and measured deformation rates confirms that the recommended values of the temperature-dependent flow rate factor A are a good choice for ice-sheet models. Text glacier Greenland Ice Sheet Dartmouth Digital Commons (Dartmouth College) Greenland Journal of Glaciology 60 222 647 660 |
institution |
Open Polar |
collection |
Dartmouth Digital Commons (Dartmouth College) |
op_collection_id |
ftdartmouthcoll |
language |
unknown |
topic |
polar region ice sheets seasonal variations borehole glacier bed basal ice deformation measurement rheology flow velocity modeling marginal ice zone Earth Sciences Glaciology Physical Sciences and Mathematics |
spellingShingle |
polar region ice sheets seasonal variations borehole glacier bed basal ice deformation measurement rheology flow velocity modeling marginal ice zone Earth Sciences Glaciology Physical Sciences and Mathematics Ryser, Claudia Lüthi, Martin P Andrews, Lauren C Hoffman, Matthew J Catania, Ginny A Hawley, Robert L Sustained High Basal Motion of the Greenland Ice Sheet Revealed by Borehole Deformation |
topic_facet |
polar region ice sheets seasonal variations borehole glacier bed basal ice deformation measurement rheology flow velocity modeling marginal ice zone Earth Sciences Glaciology Physical Sciences and Mathematics |
description |
Ice deformation and basal motion characterize the dynamical behavior of the Greenland ice sheet (GrIS). We evaluate the contribution of basal motion from ice deformation measurements in boreholes drilled to the bed at two sites in the western marginal zone of the GrIS. We find a sustained high amount of basal motion contribution to surface velocity of 44–73% in winter, and up to 90% in summer. Measured ice deformation rates show an unexpected variation with depth that can be explained with the help of an ice-flow model as a consequence of stress transfer from slippery to sticky areas. This effect necessitates the use of high-order ice-flow models, not only in regions of fast-flowing ice streams but in all temperate-based areas of the GrIS. The agreement between modeled and measured deformation rates confirms that the recommended values of the temperature-dependent flow rate factor A are a good choice for ice-sheet models. |
format |
Text |
author |
Ryser, Claudia Lüthi, Martin P Andrews, Lauren C Hoffman, Matthew J Catania, Ginny A Hawley, Robert L |
author_facet |
Ryser, Claudia Lüthi, Martin P Andrews, Lauren C Hoffman, Matthew J Catania, Ginny A Hawley, Robert L |
author_sort |
Ryser, Claudia |
title |
Sustained High Basal Motion of the Greenland Ice Sheet Revealed by Borehole Deformation |
title_short |
Sustained High Basal Motion of the Greenland Ice Sheet Revealed by Borehole Deformation |
title_full |
Sustained High Basal Motion of the Greenland Ice Sheet Revealed by Borehole Deformation |
title_fullStr |
Sustained High Basal Motion of the Greenland Ice Sheet Revealed by Borehole Deformation |
title_full_unstemmed |
Sustained High Basal Motion of the Greenland Ice Sheet Revealed by Borehole Deformation |
title_sort |
sustained high basal motion of the greenland ice sheet revealed by borehole deformation |
publisher |
Dartmouth Digital Commons |
publishDate |
2014 |
url |
https://digitalcommons.dartmouth.edu/facoa/1753 https://doi.org/10.3189/2014JoG13J196 https://digitalcommons.dartmouth.edu/context/facoa/article/2756/viewcontent/sustained_high_basal_motion_of_the_greenland_ice_sheet_revealed_by_borehole_deformation.pdf |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
glacier Greenland Ice Sheet |
genre_facet |
glacier Greenland Ice Sheet |
op_source |
Dartmouth Scholarship |
op_relation |
https://digitalcommons.dartmouth.edu/facoa/1753 doi:10.3189/2014JoG13J196 https://digitalcommons.dartmouth.edu/context/facoa/article/2756/viewcontent/sustained_high_basal_motion_of_the_greenland_ice_sheet_revealed_by_borehole_deformation.pdf |
op_doi |
https://doi.org/10.3189/2014JoG13J196 |
container_title |
Journal of Glaciology |
container_volume |
60 |
container_issue |
222 |
container_start_page |
647 |
op_container_end_page |
660 |
_version_ |
1771545733644681216 |