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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ftnasantrs:oai:casi.ntrs.nasa.gov:20150014255 2023-05-15T16:27:39+02:00 Sustained High Basal Motion of the Greenland Ice Sheet Revealed by Borehole Deformation Neumann, Thomas A. Hawley, Robert L. Luthi, Martin P. Andrews, Lauren C. Hoffman, Matthew, J. Ryser, Claudia Kristensen, Steen S. Catania, Ginny A. Unclassified, Unlimited, Publicly available October 1, 2014 application/pdf http://hdl.handle.net/2060/20150014255 unknown Document ID: 20150014255 http://hdl.handle.net/2060/20150014255 Copyright, Distribution as joint owner in the copyright CASI Meteorology and Climatology Earth Resources and Remote Sensing GSFC-E-DAA-TN21958 Journal of Glaciology (ISSN 1727-5652); 60; 222; 647-660 2014 ftnasantrs 2019-07-21T00:06:16Z 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 percent in winter, and up to 90 percent 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. Other/Unknown Material 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 |
Meteorology and Climatology Earth Resources and Remote Sensing |
spellingShingle |
Meteorology and Climatology Earth Resources and Remote Sensing Neumann, Thomas A. Hawley, Robert L. Luthi, Martin P. Andrews, Lauren C. Hoffman, Matthew, J. Ryser, Claudia Kristensen, Steen S. Catania, Ginny A. Sustained High Basal Motion of the Greenland Ice Sheet Revealed by Borehole Deformation |
topic_facet |
Meteorology and Climatology Earth Resources and Remote Sensing |
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 percent in winter, and up to 90 percent 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 |
Other/Unknown Material |
author |
Neumann, Thomas A. Hawley, Robert L. Luthi, Martin P. Andrews, Lauren C. Hoffman, Matthew, J. Ryser, Claudia Kristensen, Steen S. Catania, Ginny A. |
author_facet |
Neumann, Thomas A. Hawley, Robert L. Luthi, Martin P. Andrews, Lauren C. Hoffman, Matthew, J. Ryser, Claudia Kristensen, Steen S. Catania, Ginny A. |
author_sort |
Neumann, Thomas A. |
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 |
publishDate |
2014 |
url |
http://hdl.handle.net/2060/20150014255 |
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: 20150014255 http://hdl.handle.net/2060/20150014255 |
op_rights |
Copyright, Distribution as joint owner in the copyright |
_version_ |
1766017104327213056 |