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...
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Cambridge University Press
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ftdoajarticles:oai:doaj.org/article:916f6fa739ea4c4588eef0bc078325fa 2023-05-15T13:49:53+02:00 Processes controlling the downstream evolution of ice rheology in glacier shear margins: case study on Rutford Ice Stream, West Antarctica BRENT M. MINCHEW COLIN R. MEYER ALEXANDER A. ROBEL G. HILMAR GUDMUNDSSON MARK SIMONS 2018-08-01T00:00:00Z https://doi.org/10.1017/jog.2018.47 https://doaj.org/article/916f6fa739ea4c4588eef0bc078325fa EN eng Cambridge University Press https://www.cambridge.org/core/product/identifier/S0022143018000473/type/journal_article https://doaj.org/toc/0022-1430 https://doaj.org/toc/1727-5652 doi:10.1017/jog.2018.47 0022-1430 1727-5652 https://doaj.org/article/916f6fa739ea4c4588eef0bc078325fa Journal of Glaciology, Vol 64, Pp 583-594 (2018) Anisotropic ice flow Antarctic glaciology glacial rheology glacier flow ice rheology Environmental sciences GE1-350 Meteorology. Climatology QC851-999 article 2018 ftdoajarticles https://doi.org/10.1017/jog.2018.47 2023-03-12T01:30:59Z 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* Antarctic Antarctica Ice Stream A Journal of Glaciology Rutford Ice Stream West Antarctica Directory of Open Access Journals: DOAJ Articles Antarctic West Antarctica Rutford ENVELOPE(-85.300,-85.300,-78.600,-78.600) Rutford Ice Stream ENVELOPE(-80.000,-80.000,-79.167,-79.167) Journal of Glaciology 64 246 583 594 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Anisotropic ice flow Antarctic glaciology glacial rheology glacier flow ice rheology Environmental sciences GE1-350 Meteorology. Climatology QC851-999 |
spellingShingle |
Anisotropic ice flow Antarctic glaciology glacial rheology glacier flow ice rheology Environmental sciences GE1-350 Meteorology. Climatology QC851-999 BRENT M. MINCHEW COLIN R. MEYER ALEXANDER A. ROBEL G. HILMAR GUDMUNDSSON MARK SIMONS Processes controlling the downstream evolution of ice rheology in glacier shear margins: case study on Rutford Ice Stream, West Antarctica |
topic_facet |
Anisotropic ice flow Antarctic glaciology glacial rheology glacier flow ice rheology Environmental sciences GE1-350 Meteorology. Climatology QC851-999 |
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 |
BRENT M. MINCHEW COLIN R. MEYER ALEXANDER A. ROBEL G. HILMAR GUDMUNDSSON MARK SIMONS |
author_facet |
BRENT M. MINCHEW COLIN R. MEYER ALEXANDER A. ROBEL G. HILMAR GUDMUNDSSON MARK SIMONS |
author_sort |
BRENT M. MINCHEW |
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 |
Cambridge University Press |
publishDate |
2018 |
url |
https://doi.org/10.1017/jog.2018.47 https://doaj.org/article/916f6fa739ea4c4588eef0bc078325fa |
long_lat |
ENVELOPE(-85.300,-85.300,-78.600,-78.600) ENVELOPE(-80.000,-80.000,-79.167,-79.167) |
geographic |
Antarctic West Antarctica Rutford Rutford Ice Stream |
geographic_facet |
Antarctic West Antarctica Rutford Rutford Ice Stream |
genre |
Antarc* Antarctic Antarctica Ice Stream A Journal of Glaciology Rutford Ice Stream West Antarctica |
genre_facet |
Antarc* Antarctic Antarctica Ice Stream A Journal of Glaciology Rutford Ice Stream West Antarctica |
op_source |
Journal of Glaciology, Vol 64, Pp 583-594 (2018) |
op_relation |
https://www.cambridge.org/core/product/identifier/S0022143018000473/type/journal_article https://doaj.org/toc/0022-1430 https://doaj.org/toc/1727-5652 doi:10.1017/jog.2018.47 0022-1430 1727-5652 https://doaj.org/article/916f6fa739ea4c4588eef0bc078325fa |
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_ |
1766252476396208128 |