Effective rheology across the fragmentation transition for sea ice and ice shelves
Sea ice and ice shelves can be described by a viscoelastic rheology that is approximately linear elastic and brittle at high strain rates, and viscously shear‐thinning at low strain rates. Brittle ice easily fractures under compressive shear and forms shear bands as the material undergoes a transiti...
Published in: | Geophysical Research Letters |
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Format: | Article in Journal/Newspaper |
Language: | English |
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2019
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Online Access: | https://risweb.st-andrews.ac.uk/portal/en/researchoutput/effective-rheology-across-the-fragmentation-transition-for-sea-ice-and-ice-shelves(f7894529-fbcf-4e25-838f-eca7daf618f3).html https://doi.org/10.1029/2019GL084896 https://research-repository.st-andrews.ac.uk/bitstream/10023/19967/1/_str_m_2019_GRL_Rheology_FinalPubVersion.pdf |
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ftunstandrewcris:oai:risweb.st-andrews.ac.uk:publications/f7894529-fbcf-4e25-838f-eca7daf618f3 2023-05-15T13:51:52+02:00 Effective rheology across the fragmentation transition for sea ice and ice shelves Åström, J.A. Benn, D.I. 2019-11-20 application/pdf https://risweb.st-andrews.ac.uk/portal/en/researchoutput/effective-rheology-across-the-fragmentation-transition-for-sea-ice-and-ice-shelves(f7894529-fbcf-4e25-838f-eca7daf618f3).html https://doi.org/10.1029/2019GL084896 https://research-repository.st-andrews.ac.uk/bitstream/10023/19967/1/_str_m_2019_GRL_Rheology_FinalPubVersion.pdf eng eng info:eu-repo/semantics/openAccess Åström , J A & Benn , D I 2019 , ' Effective rheology across the fragmentation transition for sea ice and ice shelves ' , Geophysical Research Letters , vol. Early View . https://doi.org/10.1029/2019GL084896 Ice shelves Sea ice Modelling article 2019 ftunstandrewcris https://doi.org/10.1029/2019GL084896 2021-12-26T14:35:34Z Sea ice and ice shelves can be described by a viscoelastic rheology that is approximately linear elastic and brittle at high strain rates, and viscously shear‐thinning at low strain rates. Brittle ice easily fractures under compressive shear and forms shear bands as the material undergoes a transition to a fragmented, granular state. This transition plays a central role in the mechanical behaviour at large scales of sea‐ice in the Arctic Ocean or Antarctic ice shelves. Here we demonstrate that the fragmentation transition is characterized by an essentially discontinuous drop of 3‐5 orders of magnitude in effective viscosity and stress‐relaxation time. Beyond the fragmentation transition, grinding in shear zones further reduces both effective viscosity and shear stiffness, but with an essentially constant relaxation time of ∼10second. These results are relevant for ice‐rheology implementation in large‐scale climate‐related models of sea ice and thin ice shelves. Article in Journal/Newspaper Antarc* Antarctic Arctic Arctic Ocean Ice Shelves Sea ice University of St Andrews: Research Portal Antarctic Arctic Arctic Ocean Geophysical Research Letters 46 22 13099 13106 |
institution |
Open Polar |
collection |
University of St Andrews: Research Portal |
op_collection_id |
ftunstandrewcris |
language |
English |
topic |
Ice shelves Sea ice Modelling |
spellingShingle |
Ice shelves Sea ice Modelling Åström, J.A. Benn, D.I. Effective rheology across the fragmentation transition for sea ice and ice shelves |
topic_facet |
Ice shelves Sea ice Modelling |
description |
Sea ice and ice shelves can be described by a viscoelastic rheology that is approximately linear elastic and brittle at high strain rates, and viscously shear‐thinning at low strain rates. Brittle ice easily fractures under compressive shear and forms shear bands as the material undergoes a transition to a fragmented, granular state. This transition plays a central role in the mechanical behaviour at large scales of sea‐ice in the Arctic Ocean or Antarctic ice shelves. Here we demonstrate that the fragmentation transition is characterized by an essentially discontinuous drop of 3‐5 orders of magnitude in effective viscosity and stress‐relaxation time. Beyond the fragmentation transition, grinding in shear zones further reduces both effective viscosity and shear stiffness, but with an essentially constant relaxation time of ∼10second. These results are relevant for ice‐rheology implementation in large‐scale climate‐related models of sea ice and thin ice shelves. |
format |
Article in Journal/Newspaper |
author |
Åström, J.A. Benn, D.I. |
author_facet |
Åström, J.A. Benn, D.I. |
author_sort |
Åström, J.A. |
title |
Effective rheology across the fragmentation transition for sea ice and ice shelves |
title_short |
Effective rheology across the fragmentation transition for sea ice and ice shelves |
title_full |
Effective rheology across the fragmentation transition for sea ice and ice shelves |
title_fullStr |
Effective rheology across the fragmentation transition for sea ice and ice shelves |
title_full_unstemmed |
Effective rheology across the fragmentation transition for sea ice and ice shelves |
title_sort |
effective rheology across the fragmentation transition for sea ice and ice shelves |
publishDate |
2019 |
url |
https://risweb.st-andrews.ac.uk/portal/en/researchoutput/effective-rheology-across-the-fragmentation-transition-for-sea-ice-and-ice-shelves(f7894529-fbcf-4e25-838f-eca7daf618f3).html https://doi.org/10.1029/2019GL084896 https://research-repository.st-andrews.ac.uk/bitstream/10023/19967/1/_str_m_2019_GRL_Rheology_FinalPubVersion.pdf |
geographic |
Antarctic Arctic Arctic Ocean |
geographic_facet |
Antarctic Arctic Arctic Ocean |
genre |
Antarc* Antarctic Arctic Arctic Ocean Ice Shelves Sea ice |
genre_facet |
Antarc* Antarctic Arctic Arctic Ocean Ice Shelves Sea ice |
op_source |
Åström , J A & Benn , D I 2019 , ' Effective rheology across the fragmentation transition for sea ice and ice shelves ' , Geophysical Research Letters , vol. Early View . https://doi.org/10.1029/2019GL084896 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1029/2019GL084896 |
container_title |
Geophysical Research Letters |
container_volume |
46 |
container_issue |
22 |
container_start_page |
13099 |
op_container_end_page |
13106 |
_version_ |
1766255914672717824 |