Buoyant forces promote tidewater glacier iceberg calving through large basal stress concentrations
Iceberg calving parameterisations currently implemented in ice sheet models do not reproduce the full observed range of calving behaviours. For example, though buoyant forces at the ice front are known to trigger full-depth calving events on major Greenland outlet glaciers, a multi-stage iceberg cal...
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ftdoajarticles:oai:doaj.org/article:065897a0a1d34ba6a889f8ae09298d38 2023-05-15T16:21:26+02:00 Buoyant forces promote tidewater glacier iceberg calving through large basal stress concentrations M. Trevers A. J. Payne S. L. Cornford T. Moon 2019-07-01T00:00:00Z https://doi.org/10.5194/tc-13-1877-2019 https://doaj.org/article/065897a0a1d34ba6a889f8ae09298d38 EN eng Copernicus Publications https://www.the-cryosphere.net/13/1877/2019/tc-13-1877-2019.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-13-1877-2019 1994-0416 1994-0424 https://doaj.org/article/065897a0a1d34ba6a889f8ae09298d38 The Cryosphere, Vol 13, Pp 1877-1887 (2019) Environmental sciences GE1-350 Geology QE1-996.5 article 2019 ftdoajarticles https://doi.org/10.5194/tc-13-1877-2019 2022-12-31T12:09:24Z Iceberg calving parameterisations currently implemented in ice sheet models do not reproduce the full observed range of calving behaviours. For example, though buoyant forces at the ice front are known to trigger full-depth calving events on major Greenland outlet glaciers, a multi-stage iceberg calving event at Jakobshavn Isbræ is unexplained by existing models. To explain this and similar events, we propose a notch-triggered rotation mechanism, whereby a relatively small subaerial calving event triggers a larger full-depth calving event due to the abrupt increase in buoyant load and the associated stresses generated at the ice–bed interface. We investigate the notch-triggered rotation mechanism by applying a geometric perturbation to the subaerial section of the calving front in a diagnostic flow-line model of an idealised glacier snout, using the full-Stokes, finite element method code Elmer/Ice. Different sliding laws and water pressure boundary conditions are applied at the ice–bed interface. Water pressure has a big influence on the likelihood of calving, and stress concentrations large enough to open crevasses were generated in basal ice. Significantly, the location of stress concentrations produced calving events of approximately the size observed, providing support for future application of the notch-triggered rotation mechanism in ice-sheet models. Article in Journal/Newspaper glacier Greenland Ice Sheet Jakobshavn Jakobshavn isbræ The Cryosphere Tidewater Directory of Open Access Journals: DOAJ Articles Greenland Jakobshavn Isbræ ENVELOPE(-49.917,-49.917,69.167,69.167) The Cryosphere 13 7 1877 1887 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental sciences GE1-350 Geology QE1-996.5 |
spellingShingle |
Environmental sciences GE1-350 Geology QE1-996.5 M. Trevers A. J. Payne S. L. Cornford T. Moon Buoyant forces promote tidewater glacier iceberg calving through large basal stress concentrations |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
Iceberg calving parameterisations currently implemented in ice sheet models do not reproduce the full observed range of calving behaviours. For example, though buoyant forces at the ice front are known to trigger full-depth calving events on major Greenland outlet glaciers, a multi-stage iceberg calving event at Jakobshavn Isbræ is unexplained by existing models. To explain this and similar events, we propose a notch-triggered rotation mechanism, whereby a relatively small subaerial calving event triggers a larger full-depth calving event due to the abrupt increase in buoyant load and the associated stresses generated at the ice–bed interface. We investigate the notch-triggered rotation mechanism by applying a geometric perturbation to the subaerial section of the calving front in a diagnostic flow-line model of an idealised glacier snout, using the full-Stokes, finite element method code Elmer/Ice. Different sliding laws and water pressure boundary conditions are applied at the ice–bed interface. Water pressure has a big influence on the likelihood of calving, and stress concentrations large enough to open crevasses were generated in basal ice. Significantly, the location of stress concentrations produced calving events of approximately the size observed, providing support for future application of the notch-triggered rotation mechanism in ice-sheet models. |
format |
Article in Journal/Newspaper |
author |
M. Trevers A. J. Payne S. L. Cornford T. Moon |
author_facet |
M. Trevers A. J. Payne S. L. Cornford T. Moon |
author_sort |
M. Trevers |
title |
Buoyant forces promote tidewater glacier iceberg calving through large basal stress concentrations |
title_short |
Buoyant forces promote tidewater glacier iceberg calving through large basal stress concentrations |
title_full |
Buoyant forces promote tidewater glacier iceberg calving through large basal stress concentrations |
title_fullStr |
Buoyant forces promote tidewater glacier iceberg calving through large basal stress concentrations |
title_full_unstemmed |
Buoyant forces promote tidewater glacier iceberg calving through large basal stress concentrations |
title_sort |
buoyant forces promote tidewater glacier iceberg calving through large basal stress concentrations |
publisher |
Copernicus Publications |
publishDate |
2019 |
url |
https://doi.org/10.5194/tc-13-1877-2019 https://doaj.org/article/065897a0a1d34ba6a889f8ae09298d38 |
long_lat |
ENVELOPE(-49.917,-49.917,69.167,69.167) |
geographic |
Greenland Jakobshavn Isbræ |
geographic_facet |
Greenland Jakobshavn Isbræ |
genre |
glacier Greenland Ice Sheet Jakobshavn Jakobshavn isbræ The Cryosphere Tidewater |
genre_facet |
glacier Greenland Ice Sheet Jakobshavn Jakobshavn isbræ The Cryosphere Tidewater |
op_source |
The Cryosphere, Vol 13, Pp 1877-1887 (2019) |
op_relation |
https://www.the-cryosphere.net/13/1877/2019/tc-13-1877-2019.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-13-1877-2019 1994-0416 1994-0424 https://doaj.org/article/065897a0a1d34ba6a889f8ae09298d38 |
op_doi |
https://doi.org/10.5194/tc-13-1877-2019 |
container_title |
The Cryosphere |
container_volume |
13 |
container_issue |
7 |
container_start_page |
1877 |
op_container_end_page |
1887 |
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1766009432596021248 |