Basal traction mainly dictated by hard-bed physics over grounded regions of Greenland
International audience On glaciers and ice sheets, identifying the relationship between velocity and traction is critical to constrain the bed physics that controls ice flow. Yet in Greenland, these relationships remain unquantified. We determine the spatial relationship between velocity and tractio...
Published in: | The Cryosphere |
---|---|
Main Authors: | , , , |
Other Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
2021
|
Subjects: | |
Online Access: | https://hal.archives-ouvertes.fr/hal-03454607 https://hal.archives-ouvertes.fr/hal-03454607/document https://hal.archives-ouvertes.fr/hal-03454607/file/Maier2021.pdf https://doi.org/10.5194/tc-15-1435-2021 |
id |
ftccsdartic:oai:HAL:hal-03454607v1 |
---|---|
record_format |
openpolar |
spelling |
ftccsdartic:oai:HAL:hal-03454607v1 2023-05-15T16:24:33+02:00 Basal traction mainly dictated by hard-bed physics over grounded regions of Greenland Maier, Nathan Gimbert, Florent Gillet-Chaulet, Fabien Gilbert, Adrien Institut des Géosciences de l’Environnement (IGE) Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement (IRD)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ) Université Grenoble Alpes (UGA) 2021-03-22 https://hal.archives-ouvertes.fr/hal-03454607 https://hal.archives-ouvertes.fr/hal-03454607/document https://hal.archives-ouvertes.fr/hal-03454607/file/Maier2021.pdf https://doi.org/10.5194/tc-15-1435-2021 en eng HAL CCSD Copernicus info:eu-repo/semantics/altIdentifier/doi/10.5194/tc-15-1435-2021 hal-03454607 https://hal.archives-ouvertes.fr/hal-03454607 https://hal.archives-ouvertes.fr/hal-03454607/document https://hal.archives-ouvertes.fr/hal-03454607/file/Maier2021.pdf doi:10.5194/tc-15-1435-2021 info:eu-repo/semantics/OpenAccess ISSN: 1994-0424 EISSN: 1994-0416 The Cryosphere https://hal.archives-ouvertes.fr/hal-03454607 The Cryosphere, Copernicus 2021, 15, pp.1435 - 1451. ⟨10.5194/tc-15-1435-2021⟩ [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment info:eu-repo/semantics/article Journal articles 2021 ftccsdartic https://doi.org/10.5194/tc-15-1435-2021 2022-01-08T23:48:20Z International audience On glaciers and ice sheets, identifying the relationship between velocity and traction is critical to constrain the bed physics that controls ice flow. Yet in Greenland, these relationships remain unquantified. We determine the spatial relationship between velocity and traction in all eight major drainage catchments of Greenland. The basal traction is estimated using three different methods over large grid cells to minimize interpretation biases associated with unconstrained rheologic parameters used in numerical inversions. We find the relationships are consistent with our current understanding of basal physics in each catchment. We identify catchments that predominantly show Mohr-Coulomb-like behavior typical of deforming beds or significant cavitation, as well as catchments that predominantly show rate-strengthening behavior typical of Weertman-type hard-bed physics. Overall, the traction relationships suggest that the flow field and surface geometry of the grounded regions in Greenland is mainly dictated by Weertman-type hard-bed physics up to velocities of approximately 450 m yr −1 , except within the Northeast Greenland Ice Stream and areas near floatation. Depending on the catchment, behavior of the fastest-flowing ice (∼ 1000 m yr −1) directly inland from marine-terminating outlets exhibits Weertman-type rate strengthening, Mohr-Coulomb-like behavior, or is not confidently resolved given our methodology. Given the complex basal boundary across Greenland, the relationships are captured reasonably well by simple traction laws which provide a parameterization that can be used to model ice dynamics at large scales. The results and analysis serve as a first constraint on the physics of basal motion over the grounded regions of Greenland and provide unique insight into future dynamics and vulnerabilities in a warming climate. Article in Journal/Newspaper Greenland The Cryosphere Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) Greenland Weertman ENVELOPE(-67.753,-67.753,-66.972,-66.972) The Cryosphere 15 3 1435 1451 |
institution |
Open Polar |
collection |
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) |
op_collection_id |
ftccsdartic |
language |
English |
topic |
[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment |
spellingShingle |
[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment Maier, Nathan Gimbert, Florent Gillet-Chaulet, Fabien Gilbert, Adrien Basal traction mainly dictated by hard-bed physics over grounded regions of Greenland |
topic_facet |
[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment |
description |
International audience On glaciers and ice sheets, identifying the relationship between velocity and traction is critical to constrain the bed physics that controls ice flow. Yet in Greenland, these relationships remain unquantified. We determine the spatial relationship between velocity and traction in all eight major drainage catchments of Greenland. The basal traction is estimated using three different methods over large grid cells to minimize interpretation biases associated with unconstrained rheologic parameters used in numerical inversions. We find the relationships are consistent with our current understanding of basal physics in each catchment. We identify catchments that predominantly show Mohr-Coulomb-like behavior typical of deforming beds or significant cavitation, as well as catchments that predominantly show rate-strengthening behavior typical of Weertman-type hard-bed physics. Overall, the traction relationships suggest that the flow field and surface geometry of the grounded regions in Greenland is mainly dictated by Weertman-type hard-bed physics up to velocities of approximately 450 m yr −1 , except within the Northeast Greenland Ice Stream and areas near floatation. Depending on the catchment, behavior of the fastest-flowing ice (∼ 1000 m yr −1) directly inland from marine-terminating outlets exhibits Weertman-type rate strengthening, Mohr-Coulomb-like behavior, or is not confidently resolved given our methodology. Given the complex basal boundary across Greenland, the relationships are captured reasonably well by simple traction laws which provide a parameterization that can be used to model ice dynamics at large scales. The results and analysis serve as a first constraint on the physics of basal motion over the grounded regions of Greenland and provide unique insight into future dynamics and vulnerabilities in a warming climate. |
author2 |
Institut des Géosciences de l’Environnement (IGE) Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement (IRD)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ) Université Grenoble Alpes (UGA) |
format |
Article in Journal/Newspaper |
author |
Maier, Nathan Gimbert, Florent Gillet-Chaulet, Fabien Gilbert, Adrien |
author_facet |
Maier, Nathan Gimbert, Florent Gillet-Chaulet, Fabien Gilbert, Adrien |
author_sort |
Maier, Nathan |
title |
Basal traction mainly dictated by hard-bed physics over grounded regions of Greenland |
title_short |
Basal traction mainly dictated by hard-bed physics over grounded regions of Greenland |
title_full |
Basal traction mainly dictated by hard-bed physics over grounded regions of Greenland |
title_fullStr |
Basal traction mainly dictated by hard-bed physics over grounded regions of Greenland |
title_full_unstemmed |
Basal traction mainly dictated by hard-bed physics over grounded regions of Greenland |
title_sort |
basal traction mainly dictated by hard-bed physics over grounded regions of greenland |
publisher |
HAL CCSD |
publishDate |
2021 |
url |
https://hal.archives-ouvertes.fr/hal-03454607 https://hal.archives-ouvertes.fr/hal-03454607/document https://hal.archives-ouvertes.fr/hal-03454607/file/Maier2021.pdf https://doi.org/10.5194/tc-15-1435-2021 |
long_lat |
ENVELOPE(-67.753,-67.753,-66.972,-66.972) |
geographic |
Greenland Weertman |
geographic_facet |
Greenland Weertman |
genre |
Greenland The Cryosphere |
genre_facet |
Greenland The Cryosphere |
op_source |
ISSN: 1994-0424 EISSN: 1994-0416 The Cryosphere https://hal.archives-ouvertes.fr/hal-03454607 The Cryosphere, Copernicus 2021, 15, pp.1435 - 1451. ⟨10.5194/tc-15-1435-2021⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/tc-15-1435-2021 hal-03454607 https://hal.archives-ouvertes.fr/hal-03454607 https://hal.archives-ouvertes.fr/hal-03454607/document https://hal.archives-ouvertes.fr/hal-03454607/file/Maier2021.pdf doi:10.5194/tc-15-1435-2021 |
op_rights |
info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.5194/tc-15-1435-2021 |
container_title |
The Cryosphere |
container_volume |
15 |
container_issue |
3 |
container_start_page |
1435 |
op_container_end_page |
1451 |
_version_ |
1766013035729649664 |