Towards modelling of corrugation ridges at ice-sheet grounding lines
Improvements in the resolution of sea-floor mapping techniques have revealed extremely regular, sub-metre-scale ridge landforms produced by the tidal flexure of ice-shelf grounding lines as they retreated very rapidly (i.e. at rates of several kilometres per year). Guided by such novel sea-floor obs...
Published in: | The Cryosphere |
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Copernicus Publications
2023
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ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00067656 2023-07-30T03:57:42+02:00 Towards modelling of corrugation ridges at ice-sheet grounding lines Hogan, Kelly A. Warburton, Katarzyna L. P. Graham, Alastair G. C. Neufeld, Jerome A. Hewitt, Duncan R. Dowdeswell, Julian A. Larter, Robert D. 2023-07 electronic https://doi.org/10.5194/tc-17-2645-2023 https://noa.gwlb.de/receive/cop_mods_00067656 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00066105/tc-17-2645-2023.pdf https://tc.copernicus.org/articles/17/2645/2023/tc-17-2645-2023.pdf eng eng Copernicus Publications The Cryosphere -- ˜Theœ Cryosphere -- http://www.bibliothek.uni-regensburg.de/ezeit/?2393169 -- http://www.the-cryosphere.net/ -- 1994-0424 https://doi.org/10.5194/tc-17-2645-2023 https://noa.gwlb.de/receive/cop_mods_00067656 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00066105/tc-17-2645-2023.pdf https://tc.copernicus.org/articles/17/2645/2023/tc-17-2645-2023.pdf https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess article Verlagsveröffentlichung article Text doc-type:article 2023 ftnonlinearchiv https://doi.org/10.5194/tc-17-2645-2023 2023-07-16T23:19:17Z Improvements in the resolution of sea-floor mapping techniques have revealed extremely regular, sub-metre-scale ridge landforms produced by the tidal flexure of ice-shelf grounding lines as they retreated very rapidly (i.e. at rates of several kilometres per year). Guided by such novel sea-floor observations from Thwaites Glacier, West Antarctica, we present three mathematical models for the formation of these corrugation ridges at a tidally migrating grounding line (that is retreating at a constant rate), where each ridge is formed by either constant till flux to the grounding line, till extrusion from the grounding line, or the resuspension and transport of grains from the grounding-zone bed. We find that both till extrusion (squeezing out till like toothpaste as the ice sheet re-settles on the sea floor) and resuspension and transport of material can qualitatively reproduce regular, delicate ridges at a retreating grounding line, as described by sea-floor observations. By considering the known properties of subglacial sediments, we agree with existing schematic models that the most likely mechanism for ridge formation is till extrusion at each low-tide position, essentially preserving an imprint of the ice-sheet grounding line as it retreated. However, when realistic (shallow) bed slopes are used in the simulations, ridges start to overprint one another, suggesting that, to preserve the regular ridges that have been observed, grounding line retreat rates (driven by dynamic thinning?) may be even higher than previously thought. Article in Journal/Newspaper Antarc* Antarctica Ice Sheet Ice Shelf The Cryosphere Thwaites Glacier West Antarctica Niedersächsisches Online-Archiv NOA Thwaites Glacier ENVELOPE(-106.750,-106.750,-75.500,-75.500) West Antarctica The Cryosphere 17 7 2645 2664 |
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Open Polar |
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Niedersächsisches Online-Archiv NOA |
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language |
English |
topic |
article Verlagsveröffentlichung |
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article Verlagsveröffentlichung Hogan, Kelly A. Warburton, Katarzyna L. P. Graham, Alastair G. C. Neufeld, Jerome A. Hewitt, Duncan R. Dowdeswell, Julian A. Larter, Robert D. Towards modelling of corrugation ridges at ice-sheet grounding lines |
topic_facet |
article Verlagsveröffentlichung |
description |
Improvements in the resolution of sea-floor mapping techniques have revealed extremely regular, sub-metre-scale ridge landforms produced by the tidal flexure of ice-shelf grounding lines as they retreated very rapidly (i.e. at rates of several kilometres per year). Guided by such novel sea-floor observations from Thwaites Glacier, West Antarctica, we present three mathematical models for the formation of these corrugation ridges at a tidally migrating grounding line (that is retreating at a constant rate), where each ridge is formed by either constant till flux to the grounding line, till extrusion from the grounding line, or the resuspension and transport of grains from the grounding-zone bed. We find that both till extrusion (squeezing out till like toothpaste as the ice sheet re-settles on the sea floor) and resuspension and transport of material can qualitatively reproduce regular, delicate ridges at a retreating grounding line, as described by sea-floor observations. By considering the known properties of subglacial sediments, we agree with existing schematic models that the most likely mechanism for ridge formation is till extrusion at each low-tide position, essentially preserving an imprint of the ice-sheet grounding line as it retreated. However, when realistic (shallow) bed slopes are used in the simulations, ridges start to overprint one another, suggesting that, to preserve the regular ridges that have been observed, grounding line retreat rates (driven by dynamic thinning?) may be even higher than previously thought. |
format |
Article in Journal/Newspaper |
author |
Hogan, Kelly A. Warburton, Katarzyna L. P. Graham, Alastair G. C. Neufeld, Jerome A. Hewitt, Duncan R. Dowdeswell, Julian A. Larter, Robert D. |
author_facet |
Hogan, Kelly A. Warburton, Katarzyna L. P. Graham, Alastair G. C. Neufeld, Jerome A. Hewitt, Duncan R. Dowdeswell, Julian A. Larter, Robert D. |
author_sort |
Hogan, Kelly A. |
title |
Towards modelling of corrugation ridges at ice-sheet grounding lines |
title_short |
Towards modelling of corrugation ridges at ice-sheet grounding lines |
title_full |
Towards modelling of corrugation ridges at ice-sheet grounding lines |
title_fullStr |
Towards modelling of corrugation ridges at ice-sheet grounding lines |
title_full_unstemmed |
Towards modelling of corrugation ridges at ice-sheet grounding lines |
title_sort |
towards modelling of corrugation ridges at ice-sheet grounding lines |
publisher |
Copernicus Publications |
publishDate |
2023 |
url |
https://doi.org/10.5194/tc-17-2645-2023 https://noa.gwlb.de/receive/cop_mods_00067656 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00066105/tc-17-2645-2023.pdf https://tc.copernicus.org/articles/17/2645/2023/tc-17-2645-2023.pdf |
long_lat |
ENVELOPE(-106.750,-106.750,-75.500,-75.500) |
geographic |
Thwaites Glacier West Antarctica |
geographic_facet |
Thwaites Glacier West Antarctica |
genre |
Antarc* Antarctica Ice Sheet Ice Shelf The Cryosphere Thwaites Glacier West Antarctica |
genre_facet |
Antarc* Antarctica Ice Sheet Ice Shelf The Cryosphere Thwaites Glacier West Antarctica |
op_relation |
The Cryosphere -- ˜Theœ Cryosphere -- http://www.bibliothek.uni-regensburg.de/ezeit/?2393169 -- http://www.the-cryosphere.net/ -- 1994-0424 https://doi.org/10.5194/tc-17-2645-2023 https://noa.gwlb.de/receive/cop_mods_00067656 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00066105/tc-17-2645-2023.pdf https://tc.copernicus.org/articles/17/2645/2023/tc-17-2645-2023.pdf |
op_rights |
https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/tc-17-2645-2023 |
container_title |
The Cryosphere |
container_volume |
17 |
container_issue |
7 |
container_start_page |
2645 |
op_container_end_page |
2664 |
_version_ |
1772818873933889536 |