Fracture of Antarctic shelf ice
We have investigated the fracture of Antarctic shelf ice core using two fracture mechanics test methods: the chevron-notched short-rod specimen loaded in tension and the chevron-notched round-bar specimen loaded in three-point bending. These tests have been used to measure the fracture initiation to...
Published in: | Journal of Geophysical Research: Solid Earth |
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American Geophysical Union
2002
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Online Access: | http://nora.nerc.ac.uk/id/eprint/17402/ https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2000JB000058 |
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ftnerc:oai:nora.nerc.ac.uk:17402 2023-05-15T13:45:12+02:00 Fracture of Antarctic shelf ice Rist, M.A. Sammonds, P.R. Oerter, H. Doake, C.S.M. 2002-01 http://nora.nerc.ac.uk/id/eprint/17402/ https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2000JB000058 unknown American Geophysical Union Rist, M.A.; Sammonds, P.R.; Oerter, H.; Doake, C.S.M. 2002 Fracture of Antarctic shelf ice. Journal of Geophysical Research, 107 (B1). ECV 2-1-ECV 2-13. https://doi.org/10.1029/2000JB000058 <https://doi.org/10.1029/2000JB000058> Publication - Article PeerReviewed 2002 ftnerc https://doi.org/10.1029/2000JB000058 2023-02-04T19:31:05Z We have investigated the fracture of Antarctic shelf ice core using two fracture mechanics test methods: the chevron-notched short-rod specimen loaded in tension and the chevron-notched round-bar specimen loaded in three-point bending. These tests have been used to measure the fracture initiation toughness, Kinit, at which crack growth starts, on samples taken through the entire thickness of the Ronne Ice Shelf, from low-density firn through consolidated meteoric ice to basal marine ice. The fracture data are presented together with depth profiles of relevant physical and mechanical properties derived from the test specimens: temperature, density, elastic modulus, and grain size. It is found that the trend in measured fracture toughness closely reflects changes in ice density and elastic modulus. We augment the experimental study by presenting a fracture mechanics analysis of ice shelf surface and basal crevassing which directly incorporates our measurements. For the examined ice shelf profiles, basal crevasses are found to be inherently unstable unless an external restraining force is imposed, which has important implications for overall ice shelf stability. On the other hand, surface crevassing is shown to be innately stable at depth. Our fracture mechanics model is used to predict local ice shelf back stresses in the vicinity of basal crevassing and is validated directly against field observations of crevasse penetration on the Ronne Ice Shelf. Article in Journal/Newspaper Antarc* Antarctic ice core Ice Shelf Ronne Ice Shelf Natural Environment Research Council: NERC Open Research Archive Antarctic Ronne Ice Shelf ENVELOPE(-61.000,-61.000,-78.500,-78.500) Journal of Geophysical Research: Solid Earth 107 B1 ECV 2-1 ECV 2-13 |
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Open Polar |
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Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
unknown |
description |
We have investigated the fracture of Antarctic shelf ice core using two fracture mechanics test methods: the chevron-notched short-rod specimen loaded in tension and the chevron-notched round-bar specimen loaded in three-point bending. These tests have been used to measure the fracture initiation toughness, Kinit, at which crack growth starts, on samples taken through the entire thickness of the Ronne Ice Shelf, from low-density firn through consolidated meteoric ice to basal marine ice. The fracture data are presented together with depth profiles of relevant physical and mechanical properties derived from the test specimens: temperature, density, elastic modulus, and grain size. It is found that the trend in measured fracture toughness closely reflects changes in ice density and elastic modulus. We augment the experimental study by presenting a fracture mechanics analysis of ice shelf surface and basal crevassing which directly incorporates our measurements. For the examined ice shelf profiles, basal crevasses are found to be inherently unstable unless an external restraining force is imposed, which has important implications for overall ice shelf stability. On the other hand, surface crevassing is shown to be innately stable at depth. Our fracture mechanics model is used to predict local ice shelf back stresses in the vicinity of basal crevassing and is validated directly against field observations of crevasse penetration on the Ronne Ice Shelf. |
format |
Article in Journal/Newspaper |
author |
Rist, M.A. Sammonds, P.R. Oerter, H. Doake, C.S.M. |
spellingShingle |
Rist, M.A. Sammonds, P.R. Oerter, H. Doake, C.S.M. Fracture of Antarctic shelf ice |
author_facet |
Rist, M.A. Sammonds, P.R. Oerter, H. Doake, C.S.M. |
author_sort |
Rist, M.A. |
title |
Fracture of Antarctic shelf ice |
title_short |
Fracture of Antarctic shelf ice |
title_full |
Fracture of Antarctic shelf ice |
title_fullStr |
Fracture of Antarctic shelf ice |
title_full_unstemmed |
Fracture of Antarctic shelf ice |
title_sort |
fracture of antarctic shelf ice |
publisher |
American Geophysical Union |
publishDate |
2002 |
url |
http://nora.nerc.ac.uk/id/eprint/17402/ https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2000JB000058 |
long_lat |
ENVELOPE(-61.000,-61.000,-78.500,-78.500) |
geographic |
Antarctic Ronne Ice Shelf |
geographic_facet |
Antarctic Ronne Ice Shelf |
genre |
Antarc* Antarctic ice core Ice Shelf Ronne Ice Shelf |
genre_facet |
Antarc* Antarctic ice core Ice Shelf Ronne Ice Shelf |
op_relation |
Rist, M.A.; Sammonds, P.R.; Oerter, H.; Doake, C.S.M. 2002 Fracture of Antarctic shelf ice. Journal of Geophysical Research, 107 (B1). ECV 2-1-ECV 2-13. https://doi.org/10.1029/2000JB000058 <https://doi.org/10.1029/2000JB000058> |
op_doi |
https://doi.org/10.1029/2000JB000058 |
container_title |
Journal of Geophysical Research: Solid Earth |
container_volume |
107 |
container_issue |
B1 |
container_start_page |
ECV 2-1 |
op_container_end_page |
ECV 2-13 |
_version_ |
1766216296609873920 |