Fracture of Antarctic shelf ice
[1] 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 initiatio...
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AMER GEOPHYSICAL UNION
2002
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ftucl:oai:eprints.ucl.ac.uk.OAI2:8874 2023-05-15T13:57:59+02:00 Fracture of Antarctic shelf ice Rist, MA Sammonds, PR Oerter, H Doake, CSM 2002-01-10 http://discovery.ucl.ac.uk/8874/ unknown AMER GEOPHYSICAL UNION J GEOPHYS RES-SOL EA , 107 (B1) , Article 2002. (2002) fracture mechanics ice crevassing experiments STRESS INTENSITY FACTORS FRESH-WATER ICE MECHANICS APPROACH BOTTOM CREVASSES MARINE ICE SEA-ICE TOUGHNESS PENETRATION RESISTANCE SPECIMEN Article 2002 ftucl 2016-12-15T23:08:32Z [1] 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, K-init, 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 Sea ice University College London: UCL Discovery Antarctic Ronne Ice Shelf ENVELOPE(-61.000,-61.000,-78.500,-78.500) |
institution |
Open Polar |
collection |
University College London: UCL Discovery |
op_collection_id |
ftucl |
language |
unknown |
topic |
fracture mechanics ice crevassing experiments STRESS INTENSITY FACTORS FRESH-WATER ICE MECHANICS APPROACH BOTTOM CREVASSES MARINE ICE SEA-ICE TOUGHNESS PENETRATION RESISTANCE SPECIMEN |
spellingShingle |
fracture mechanics ice crevassing experiments STRESS INTENSITY FACTORS FRESH-WATER ICE MECHANICS APPROACH BOTTOM CREVASSES MARINE ICE SEA-ICE TOUGHNESS PENETRATION RESISTANCE SPECIMEN Rist, MA Sammonds, PR Oerter, H Doake, CSM Fracture of Antarctic shelf ice |
topic_facet |
fracture mechanics ice crevassing experiments STRESS INTENSITY FACTORS FRESH-WATER ICE MECHANICS APPROACH BOTTOM CREVASSES MARINE ICE SEA-ICE TOUGHNESS PENETRATION RESISTANCE SPECIMEN |
description |
[1] 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, K-init, 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, MA Sammonds, PR Oerter, H Doake, CSM |
author_facet |
Rist, MA Sammonds, PR Oerter, H Doake, CSM |
author_sort |
Rist, MA |
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 |
AMER GEOPHYSICAL UNION |
publishDate |
2002 |
url |
http://discovery.ucl.ac.uk/8874/ |
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 Sea ice |
genre_facet |
Antarc* Antarctic ice core Ice Shelf Ronne Ice Shelf Sea ice |
op_source |
J GEOPHYS RES-SOL EA , 107 (B1) , Article 2002. (2002) |
_version_ |
1766265932590612480 |