Subglacial water flow over an Antarctic palaeo-ice stream bed
The subglacial hydrological system exerts a critical control on the dynamic behaviour of the overlying ice because its configuration affects the degree of basal lubrication between the ice and the bed. Yet this component of the glaciological system is notoriously hard to access and observe, particul...
Published in: | Journal of Geophysical Research: Earth Surface |
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Format: | Article in Journal/Newspaper |
Language: | English |
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American Geophysical Union
2022
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Online Access: | http://nora.nerc.ac.uk/id/eprint/531182/ https://nora.nerc.ac.uk/id/eprint/531182/1/JGR%20Earth%20Surface%20-%202022%20-%20Hogan%20-%20Subglacial%20Water%20Flow%20Over%20an%20Antarctic%20Palaeo%E2%80%90Ice%20Stream%20Bed.pdf https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2021JF006442 |
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ftnerc:oai:nora.nerc.ac.uk:531182 2023-05-15T13:41:46+02:00 Subglacial water flow over an Antarctic palaeo-ice stream bed Hogan, K.A. Arnold, N.S. Larter, R.D. Kirkham, J.D. Noormets, R. Ó Cofaigh, C. Golledge, N. Dowdeswell, J.A. 2022-02-18 text http://nora.nerc.ac.uk/id/eprint/531182/ https://nora.nerc.ac.uk/id/eprint/531182/1/JGR%20Earth%20Surface%20-%202022%20-%20Hogan%20-%20Subglacial%20Water%20Flow%20Over%20an%20Antarctic%20Palaeo%E2%80%90Ice%20Stream%20Bed.pdf https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2021JF006442 en eng American Geophysical Union https://nora.nerc.ac.uk/id/eprint/531182/1/JGR%20Earth%20Surface%20-%202022%20-%20Hogan%20-%20Subglacial%20Water%20Flow%20Over%20an%20Antarctic%20Palaeo%E2%80%90Ice%20Stream%20Bed.pdf Hogan, K.A. orcid:0000-0002-1256-8010 Arnold, N.S.; Larter, R.D. orcid:0000-0002-8414-7389 Kirkham, J.D. orcid:0000-0002-0506-1625 Noormets, R.; Ó Cofaigh, C.; Golledge, N.; Dowdeswell, J.A. 2022 Subglacial water flow over an Antarctic palaeo-ice stream bed. Journal of Geophysical Research: Earth Surface, 127 (2), e2021JF006442. 20, pp. https://doi.org/10.1029/2021JF006442 <https://doi.org/10.1029/2021JF006442> cc_by_4 CC-BY Publication - Article PeerReviewed 2022 ftnerc https://doi.org/10.1029/2021JF006442 2023-02-04T19:52:36Z The subglacial hydrological system exerts a critical control on the dynamic behaviour of the overlying ice because its configuration affects the degree of basal lubrication between the ice and the bed. Yet this component of the glaciological system is notoriously hard to access and observe, particularly over timescales longer than the satellite era. In Antarctica, abundant evidence for past subglacial water flow over former ice-sheet beds exists around the peripheries of the ice sheet including networks of huge channels carved into bedrock (now submarine) on the Pacific margin of West Antarctica. Here, we combine detailed bathymetric investigations of a channel system in Marguerite Trough, a major palaeo-ice stream bed, with numerical hydrological modelling to explore subglacial water accumulation, routing and potential for erosion over decadal-centennial timescales. Detailed channel morphologies from remotely-operated vehicle surveys indicate multiple stages of localised incision, and the occurrence of potholes – some gigantic in scale – suggests incision by turbulent water carrying a significant bedload. Further, the modelling indicates that subglacial water is available during deglaciation and was likely released in episodic drainage events, from subglacial lakes, varying in magnitude over time. Our observations support previous assertions that these huge bedrock channel systems were incised over multiple glacial cycles through episodic subglacial lake drainage events; however, here we present a viable pattern for subglacial drainage at times when the ice sheet existed over the continental shelf and was capable of continuing to erode the bedrock substrate. Article in Journal/Newspaper Antarc* Antarctic Antarctica Ice Sheet West Antarctica Natural Environment Research Council: NERC Open Research Archive Antarctic West Antarctica Pacific Marguerite ENVELOPE(141.378,141.378,-66.787,-66.787) Journal of Geophysical Research: Earth Surface 127 2 |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
English |
description |
The subglacial hydrological system exerts a critical control on the dynamic behaviour of the overlying ice because its configuration affects the degree of basal lubrication between the ice and the bed. Yet this component of the glaciological system is notoriously hard to access and observe, particularly over timescales longer than the satellite era. In Antarctica, abundant evidence for past subglacial water flow over former ice-sheet beds exists around the peripheries of the ice sheet including networks of huge channels carved into bedrock (now submarine) on the Pacific margin of West Antarctica. Here, we combine detailed bathymetric investigations of a channel system in Marguerite Trough, a major palaeo-ice stream bed, with numerical hydrological modelling to explore subglacial water accumulation, routing and potential for erosion over decadal-centennial timescales. Detailed channel morphologies from remotely-operated vehicle surveys indicate multiple stages of localised incision, and the occurrence of potholes – some gigantic in scale – suggests incision by turbulent water carrying a significant bedload. Further, the modelling indicates that subglacial water is available during deglaciation and was likely released in episodic drainage events, from subglacial lakes, varying in magnitude over time. Our observations support previous assertions that these huge bedrock channel systems were incised over multiple glacial cycles through episodic subglacial lake drainage events; however, here we present a viable pattern for subglacial drainage at times when the ice sheet existed over the continental shelf and was capable of continuing to erode the bedrock substrate. |
format |
Article in Journal/Newspaper |
author |
Hogan, K.A. Arnold, N.S. Larter, R.D. Kirkham, J.D. Noormets, R. Ó Cofaigh, C. Golledge, N. Dowdeswell, J.A. |
spellingShingle |
Hogan, K.A. Arnold, N.S. Larter, R.D. Kirkham, J.D. Noormets, R. Ó Cofaigh, C. Golledge, N. Dowdeswell, J.A. Subglacial water flow over an Antarctic palaeo-ice stream bed |
author_facet |
Hogan, K.A. Arnold, N.S. Larter, R.D. Kirkham, J.D. Noormets, R. Ó Cofaigh, C. Golledge, N. Dowdeswell, J.A. |
author_sort |
Hogan, K.A. |
title |
Subglacial water flow over an Antarctic palaeo-ice stream bed |
title_short |
Subglacial water flow over an Antarctic palaeo-ice stream bed |
title_full |
Subglacial water flow over an Antarctic palaeo-ice stream bed |
title_fullStr |
Subglacial water flow over an Antarctic palaeo-ice stream bed |
title_full_unstemmed |
Subglacial water flow over an Antarctic palaeo-ice stream bed |
title_sort |
subglacial water flow over an antarctic palaeo-ice stream bed |
publisher |
American Geophysical Union |
publishDate |
2022 |
url |
http://nora.nerc.ac.uk/id/eprint/531182/ https://nora.nerc.ac.uk/id/eprint/531182/1/JGR%20Earth%20Surface%20-%202022%20-%20Hogan%20-%20Subglacial%20Water%20Flow%20Over%20an%20Antarctic%20Palaeo%E2%80%90Ice%20Stream%20Bed.pdf https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2021JF006442 |
long_lat |
ENVELOPE(141.378,141.378,-66.787,-66.787) |
geographic |
Antarctic West Antarctica Pacific Marguerite |
geographic_facet |
Antarctic West Antarctica Pacific Marguerite |
genre |
Antarc* Antarctic Antarctica Ice Sheet West Antarctica |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet West Antarctica |
op_relation |
https://nora.nerc.ac.uk/id/eprint/531182/1/JGR%20Earth%20Surface%20-%202022%20-%20Hogan%20-%20Subglacial%20Water%20Flow%20Over%20an%20Antarctic%20Palaeo%E2%80%90Ice%20Stream%20Bed.pdf Hogan, K.A. orcid:0000-0002-1256-8010 Arnold, N.S.; Larter, R.D. orcid:0000-0002-8414-7389 Kirkham, J.D. orcid:0000-0002-0506-1625 Noormets, R.; Ó Cofaigh, C.; Golledge, N.; Dowdeswell, J.A. 2022 Subglacial water flow over an Antarctic palaeo-ice stream bed. Journal of Geophysical Research: Earth Surface, 127 (2), e2021JF006442. 20, pp. https://doi.org/10.1029/2021JF006442 <https://doi.org/10.1029/2021JF006442> |
op_rights |
cc_by_4 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1029/2021JF006442 |
container_title |
Journal of Geophysical Research: Earth Surface |
container_volume |
127 |
container_issue |
2 |
_version_ |
1766157609849585664 |