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...
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Copernicus Publications
2023
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ftdoajarticles:oai:doaj.org/article:bfe705dfaee04880802c10530208f5a0 2023-07-30T03:59:06+02:00 Towards modelling of corrugation ridges at ice-sheet grounding lines K. A. Hogan K. L. P. Warburton A. G. C. Graham J. A. Neufeld D. R. Hewitt J. A. Dowdeswell R. D. Larter 2023-07-01T00:00:00Z https://doi.org/10.5194/tc-17-2645-2023 https://doaj.org/article/bfe705dfaee04880802c10530208f5a0 EN eng Copernicus Publications https://tc.copernicus.org/articles/17/2645/2023/tc-17-2645-2023.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-17-2645-2023 1994-0416 1994-0424 https://doaj.org/article/bfe705dfaee04880802c10530208f5a0 The Cryosphere, Vol 17, Pp 2645-2664 (2023) Environmental sciences GE1-350 Geology QE1-996.5 article 2023 ftdoajarticles https://doi.org/10.5194/tc-17-2645-2023 2023-07-16T00:37:42Z 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 Directory of Open Access Journals: DOAJ Articles Thwaites Glacier ENVELOPE(-106.750,-106.750,-75.500,-75.500) West Antarctica The Cryosphere 17 7 2645 2664 |
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 K. A. Hogan K. L. P. Warburton A. G. C. Graham J. A. Neufeld D. R. Hewitt J. A. Dowdeswell R. D. Larter Towards modelling of corrugation ridges at ice-sheet grounding lines |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
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 |
K. A. Hogan K. L. P. Warburton A. G. C. Graham J. A. Neufeld D. R. Hewitt J. A. Dowdeswell R. D. Larter |
author_facet |
K. A. Hogan K. L. P. Warburton A. G. C. Graham J. A. Neufeld D. R. Hewitt J. A. Dowdeswell R. D. Larter |
author_sort |
K. A. Hogan |
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://doaj.org/article/bfe705dfaee04880802c10530208f5a0 |
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_source |
The Cryosphere, Vol 17, Pp 2645-2664 (2023) |
op_relation |
https://tc.copernicus.org/articles/17/2645/2023/tc-17-2645-2023.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-17-2645-2023 1994-0416 1994-0424 https://doaj.org/article/bfe705dfaee04880802c10530208f5a0 |
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 |
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1772809812174700544 |