Processes controlling the downstream evolution of ice rheology in glacier shear margins: case study on Rutford Ice Stream, West Antarctica
Ice rheology governs how glaciers flow and respond to environmental change. The rheology of glacier ice evolves in response to a variety of mechanisms, including damage, heating, melting and the development of crystalline fabric. The relative contributions of these rheological mechanisms are not wel...
Published in: | Journal of Glaciology |
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Language: | English |
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International Glaciological Society
2018
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Online Access: | https://nrl.northumbria.ac.uk/id/eprint/34943/ https://doi.org/10.1017/jog.2018.47 https://nrl.northumbria.ac.uk/id/eprint/34943/1/Minchew%20et%20al%20-%20Processes%20controlling%20the%20downstream%20evolution%20of%20ice%20rheology%20in%20glacier%20shear%20margins%20OA.pdf |
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ftunivnorthumb:oai:nrl.northumbria.ac.uk:34943 2023-05-15T13:56:54+02:00 Processes controlling the downstream evolution of ice rheology in glacier shear margins: case study on Rutford Ice Stream, West Antarctica Minchew, Brent M. Meyer, Colin R. Robel, Alexander A. Gudmundsson, Hilmar Simons, Mark 2018-08-01 text https://nrl.northumbria.ac.uk/id/eprint/34943/ https://doi.org/10.1017/jog.2018.47 https://nrl.northumbria.ac.uk/id/eprint/34943/1/Minchew%20et%20al%20-%20Processes%20controlling%20the%20downstream%20evolution%20of%20ice%20rheology%20in%20glacier%20shear%20margins%20OA.pdf en eng International Glaciological Society https://nrl.northumbria.ac.uk/id/eprint/34943/1/Minchew%20et%20al%20-%20Processes%20controlling%20the%20downstream%20evolution%20of%20ice%20rheology%20in%20glacier%20shear%20margins%20OA.pdf Minchew, Brent M., Meyer, Colin R., Robel, Alexander A., Gudmundsson, Hilmar and Simons, Mark (2018) Processes controlling the downstream evolution of ice rheology in glacier shear margins: case study on Rutford Ice Stream, West Antarctica. Journal of Glaciology, 64 (246). pp. 583-594. ISSN 0022-1430 cc_by_4_0 CC-BY F800 Physical and Terrestrial Geographical and Environmental Sciences Article PeerReviewed 2018 ftunivnorthumb https://doi.org/10.1017/jog.2018.47 2022-09-25T06:07:38Z Ice rheology governs how glaciers flow and respond to environmental change. The rheology of glacier ice evolves in response to a variety of mechanisms, including damage, heating, melting and the development of crystalline fabric. The relative contributions of these rheological mechanisms are not well understood. Using remotely sensed data and physical models, we decouple the influence of each of the aforementioned mechanisms along the margins of Rutford Ice Stream, a laterally confined outlet glacier in West Antarctica. We show that fabric is an important control on ice rheology in the shear margins, with an inferred softening effect consistent with a single-maximum fabric. Fabric evolves to steady state near the onset of streaming flow, and ice progressively softens downstream almost exclusively due to shear heating. The rate of heating is sensitive to local shear strain rates, which respond to local changes in bed topography as ice is squeezed through the basal trough. The impact of shear heating on the downstream evolution of ice rheology in a laterally confined glacier suggests that the thermoviscous feedback – wherein faster ice flow leads to higher rates of shear heating, further softening the ice – is a fundamental control on glacier dynamics. Article in Journal/Newspaper Antarc* Antarctica Antarctica Journal Ice Stream A Journal of Glaciology Rutford Ice Stream West Antarctica Northumbria University, Newcastle: Northumbria Research Link (NRL) Rutford ENVELOPE(-85.300,-85.300,-78.600,-78.600) Rutford Ice Stream ENVELOPE(-80.000,-80.000,-79.167,-79.167) West Antarctica Journal of Glaciology 64 246 583 594 |
institution |
Open Polar |
collection |
Northumbria University, Newcastle: Northumbria Research Link (NRL) |
op_collection_id |
ftunivnorthumb |
language |
English |
topic |
F800 Physical and Terrestrial Geographical and Environmental Sciences |
spellingShingle |
F800 Physical and Terrestrial Geographical and Environmental Sciences Minchew, Brent M. Meyer, Colin R. Robel, Alexander A. Gudmundsson, Hilmar Simons, Mark Processes controlling the downstream evolution of ice rheology in glacier shear margins: case study on Rutford Ice Stream, West Antarctica |
topic_facet |
F800 Physical and Terrestrial Geographical and Environmental Sciences |
description |
Ice rheology governs how glaciers flow and respond to environmental change. The rheology of glacier ice evolves in response to a variety of mechanisms, including damage, heating, melting and the development of crystalline fabric. The relative contributions of these rheological mechanisms are not well understood. Using remotely sensed data and physical models, we decouple the influence of each of the aforementioned mechanisms along the margins of Rutford Ice Stream, a laterally confined outlet glacier in West Antarctica. We show that fabric is an important control on ice rheology in the shear margins, with an inferred softening effect consistent with a single-maximum fabric. Fabric evolves to steady state near the onset of streaming flow, and ice progressively softens downstream almost exclusively due to shear heating. The rate of heating is sensitive to local shear strain rates, which respond to local changes in bed topography as ice is squeezed through the basal trough. The impact of shear heating on the downstream evolution of ice rheology in a laterally confined glacier suggests that the thermoviscous feedback – wherein faster ice flow leads to higher rates of shear heating, further softening the ice – is a fundamental control on glacier dynamics. |
format |
Article in Journal/Newspaper |
author |
Minchew, Brent M. Meyer, Colin R. Robel, Alexander A. Gudmundsson, Hilmar Simons, Mark |
author_facet |
Minchew, Brent M. Meyer, Colin R. Robel, Alexander A. Gudmundsson, Hilmar Simons, Mark |
author_sort |
Minchew, Brent M. |
title |
Processes controlling the downstream evolution of ice rheology in glacier shear margins: case study on Rutford Ice Stream, West Antarctica |
title_short |
Processes controlling the downstream evolution of ice rheology in glacier shear margins: case study on Rutford Ice Stream, West Antarctica |
title_full |
Processes controlling the downstream evolution of ice rheology in glacier shear margins: case study on Rutford Ice Stream, West Antarctica |
title_fullStr |
Processes controlling the downstream evolution of ice rheology in glacier shear margins: case study on Rutford Ice Stream, West Antarctica |
title_full_unstemmed |
Processes controlling the downstream evolution of ice rheology in glacier shear margins: case study on Rutford Ice Stream, West Antarctica |
title_sort |
processes controlling the downstream evolution of ice rheology in glacier shear margins: case study on rutford ice stream, west antarctica |
publisher |
International Glaciological Society |
publishDate |
2018 |
url |
https://nrl.northumbria.ac.uk/id/eprint/34943/ https://doi.org/10.1017/jog.2018.47 https://nrl.northumbria.ac.uk/id/eprint/34943/1/Minchew%20et%20al%20-%20Processes%20controlling%20the%20downstream%20evolution%20of%20ice%20rheology%20in%20glacier%20shear%20margins%20OA.pdf |
long_lat |
ENVELOPE(-85.300,-85.300,-78.600,-78.600) ENVELOPE(-80.000,-80.000,-79.167,-79.167) |
geographic |
Rutford Rutford Ice Stream West Antarctica |
geographic_facet |
Rutford Rutford Ice Stream West Antarctica |
genre |
Antarc* Antarctica Antarctica Journal Ice Stream A Journal of Glaciology Rutford Ice Stream West Antarctica |
genre_facet |
Antarc* Antarctica Antarctica Journal Ice Stream A Journal of Glaciology Rutford Ice Stream West Antarctica |
op_relation |
https://nrl.northumbria.ac.uk/id/eprint/34943/1/Minchew%20et%20al%20-%20Processes%20controlling%20the%20downstream%20evolution%20of%20ice%20rheology%20in%20glacier%20shear%20margins%20OA.pdf Minchew, Brent M., Meyer, Colin R., Robel, Alexander A., Gudmundsson, Hilmar and Simons, Mark (2018) Processes controlling the downstream evolution of ice rheology in glacier shear margins: case study on Rutford Ice Stream, West Antarctica. Journal of Glaciology, 64 (246). pp. 583-594. ISSN 0022-1430 |
op_rights |
cc_by_4_0 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1017/jog.2018.47 |
container_title |
Journal of Glaciology |
container_volume |
64 |
container_issue |
246 |
container_start_page |
583 |
op_container_end_page |
594 |
_version_ |
1766264497646862336 |