Palaeo-ice Stream Pathways and Retreat Style in the Easternmost Amundsen Sea Embayment, West Antarctica, Revealed by Combined Multibeam Bathymetric and Seismic Data
Multibeam swath bathymetry data sets collected over the past two decades have been compiled to identify palaeo-ice stream pathways in the easternmost Amundsen Sea Embayment. We mapped ~ 3000 glacial landforms to reconstruct ice flow in the ~ 250-km-long cross-shelf Abbot Trough. This bathymetric fea...
Published in: | Geomorphology |
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Digital Commons @ University of South Florida
2015
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Online Access: | https://digitalcommons.usf.edu/msc_facpub/1559 https://doi.org/10.1016/j.geomorph.2015.05.020 |
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ftunisfloridatam:oai:digitalcommons.usf.edu:msc_facpub-2551 2023-05-15T12:58:36+02:00 Palaeo-ice Stream Pathways and Retreat Style in the Easternmost Amundsen Sea Embayment, West Antarctica, Revealed by Combined Multibeam Bathymetric and Seismic Data Klages, J. P. Kuhn, G. Graham, A. G. C. Hillenbrand, C.-D. Smith, J.A. Nitsche, F. O. Larter, R. D. Gohl, K. 2015-01-01T08:00:00Z https://digitalcommons.usf.edu/msc_facpub/1559 https://doi.org/10.1016/j.geomorph.2015.05.020 unknown Digital Commons @ University of South Florida https://digitalcommons.usf.edu/msc_facpub/1559 https://doi.org/10.1016/j.geomorph.2015.05.020 Marine Science Faculty Publications West Antarctic Ice Sheet Glacial landforms Subglacial geology Basal thermal regime Ice streams Inter-ice stream ridge Ice sheet retreat Grounding-zone wedge Abbot Ice Shelf Life Sciences article 2015 ftunisfloridatam https://doi.org/10.1016/j.geomorph.2015.05.020 2022-01-20T18:38:49Z Multibeam swath bathymetry data sets collected over the past two decades have been compiled to identify palaeo-ice stream pathways in the easternmost Amundsen Sea Embayment. We mapped ~ 3000 glacial landforms to reconstruct ice flow in the ~ 250-km-long cross-shelf Abbot Trough. This bathymetric feature was occupied by a large ice stream, which was fed by two tributaries (Cosgrove and Abbot) and reached the continental shelf edge during the last maximum ice sheet advance. Geomorphological mapping has enabled a clear differentiation between subglacial landforms indicating warm- (e.g., megascale glacial lineations) and cold-based (e.g., hill–hole pairs) ice conditions on the continental shelf during the last glaciation. Grounding-zone wedges and recessional moraines, mapped within the palaeo-ice stream troughs and on adjacent sea-floor highs (referred to as inter-ice stream ridges) indicate grounding line stillstands or re-advances of the West Antarctic Ice Sheet during the last deglaciation of the shelf. We observe that the locations of grounding-zone wedges coincide with trough constrictions as well as local topographic highs of harder substrate. This combination of trough ‘bottlenecks’ and local pinning points on an otherwise retrograde slope is likely to have modified the pace of grounding-line retreat, causing the grounding zone to pause and deposit grounding-zone wedges. The episodic retreat recorded within Abbot Trough corresponds to post-glacial episodic retreat interpreted for the neighbouring Pine Island–Thwaites palaeo-ice stream trough, thus suggesting a uniform pattern of retreat across the eastern Amundsen Sea Embayment. Locally, indications are strong that a change in basal thermal regime of the ice from warm- to cold-based conditions occurred prior to final retreat, as hill–hole pairs overprint megascale glacial lineations. Further, the correlation of grounding-zone wedges with geological boundaries emphasises the influence of subglacial geology on ice stream flow. Our new geomorphological map of the easternmost Amundsen Sea Embayment resolves the pathways of palaeo-ice streams that were probably all active during the last maximum extent of the ice sheet, and the extent of adjacent inter-ice stream ridges. It reveals information about the style of, and the basal thermal regime during, the subsequent grounding line retreat. Such information provides an important empirical framework by which the accuracy of ice sheet models can be gauged. Article in Journal/Newspaper Abbot Ice Shelf Amundsen Sea Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Pine Island West Antarctica Digital Commons University of South Florida (USF) Antarctic West Antarctica Amundsen Sea West Antarctic Ice Sheet Abbot Ice Shelf ENVELOPE(-96.000,-96.000,-72.750,-72.750) Geomorphology 245 207 222 |
institution |
Open Polar |
collection |
Digital Commons University of South Florida (USF) |
op_collection_id |
ftunisfloridatam |
language |
unknown |
topic |
West Antarctic Ice Sheet Glacial landforms Subglacial geology Basal thermal regime Ice streams Inter-ice stream ridge Ice sheet retreat Grounding-zone wedge Abbot Ice Shelf Life Sciences |
spellingShingle |
West Antarctic Ice Sheet Glacial landforms Subglacial geology Basal thermal regime Ice streams Inter-ice stream ridge Ice sheet retreat Grounding-zone wedge Abbot Ice Shelf Life Sciences Klages, J. P. Kuhn, G. Graham, A. G. C. Hillenbrand, C.-D. Smith, J.A. Nitsche, F. O. Larter, R. D. Gohl, K. Palaeo-ice Stream Pathways and Retreat Style in the Easternmost Amundsen Sea Embayment, West Antarctica, Revealed by Combined Multibeam Bathymetric and Seismic Data |
topic_facet |
West Antarctic Ice Sheet Glacial landforms Subglacial geology Basal thermal regime Ice streams Inter-ice stream ridge Ice sheet retreat Grounding-zone wedge Abbot Ice Shelf Life Sciences |
description |
Multibeam swath bathymetry data sets collected over the past two decades have been compiled to identify palaeo-ice stream pathways in the easternmost Amundsen Sea Embayment. We mapped ~ 3000 glacial landforms to reconstruct ice flow in the ~ 250-km-long cross-shelf Abbot Trough. This bathymetric feature was occupied by a large ice stream, which was fed by two tributaries (Cosgrove and Abbot) and reached the continental shelf edge during the last maximum ice sheet advance. Geomorphological mapping has enabled a clear differentiation between subglacial landforms indicating warm- (e.g., megascale glacial lineations) and cold-based (e.g., hill–hole pairs) ice conditions on the continental shelf during the last glaciation. Grounding-zone wedges and recessional moraines, mapped within the palaeo-ice stream troughs and on adjacent sea-floor highs (referred to as inter-ice stream ridges) indicate grounding line stillstands or re-advances of the West Antarctic Ice Sheet during the last deglaciation of the shelf. We observe that the locations of grounding-zone wedges coincide with trough constrictions as well as local topographic highs of harder substrate. This combination of trough ‘bottlenecks’ and local pinning points on an otherwise retrograde slope is likely to have modified the pace of grounding-line retreat, causing the grounding zone to pause and deposit grounding-zone wedges. The episodic retreat recorded within Abbot Trough corresponds to post-glacial episodic retreat interpreted for the neighbouring Pine Island–Thwaites palaeo-ice stream trough, thus suggesting a uniform pattern of retreat across the eastern Amundsen Sea Embayment. Locally, indications are strong that a change in basal thermal regime of the ice from warm- to cold-based conditions occurred prior to final retreat, as hill–hole pairs overprint megascale glacial lineations. Further, the correlation of grounding-zone wedges with geological boundaries emphasises the influence of subglacial geology on ice stream flow. Our new geomorphological map of the easternmost Amundsen Sea Embayment resolves the pathways of palaeo-ice streams that were probably all active during the last maximum extent of the ice sheet, and the extent of adjacent inter-ice stream ridges. It reveals information about the style of, and the basal thermal regime during, the subsequent grounding line retreat. Such information provides an important empirical framework by which the accuracy of ice sheet models can be gauged. |
format |
Article in Journal/Newspaper |
author |
Klages, J. P. Kuhn, G. Graham, A. G. C. Hillenbrand, C.-D. Smith, J.A. Nitsche, F. O. Larter, R. D. Gohl, K. |
author_facet |
Klages, J. P. Kuhn, G. Graham, A. G. C. Hillenbrand, C.-D. Smith, J.A. Nitsche, F. O. Larter, R. D. Gohl, K. |
author_sort |
Klages, J. P. |
title |
Palaeo-ice Stream Pathways and Retreat Style in the Easternmost Amundsen Sea Embayment, West Antarctica, Revealed by Combined Multibeam Bathymetric and Seismic Data |
title_short |
Palaeo-ice Stream Pathways and Retreat Style in the Easternmost Amundsen Sea Embayment, West Antarctica, Revealed by Combined Multibeam Bathymetric and Seismic Data |
title_full |
Palaeo-ice Stream Pathways and Retreat Style in the Easternmost Amundsen Sea Embayment, West Antarctica, Revealed by Combined Multibeam Bathymetric and Seismic Data |
title_fullStr |
Palaeo-ice Stream Pathways and Retreat Style in the Easternmost Amundsen Sea Embayment, West Antarctica, Revealed by Combined Multibeam Bathymetric and Seismic Data |
title_full_unstemmed |
Palaeo-ice Stream Pathways and Retreat Style in the Easternmost Amundsen Sea Embayment, West Antarctica, Revealed by Combined Multibeam Bathymetric and Seismic Data |
title_sort |
palaeo-ice stream pathways and retreat style in the easternmost amundsen sea embayment, west antarctica, revealed by combined multibeam bathymetric and seismic data |
publisher |
Digital Commons @ University of South Florida |
publishDate |
2015 |
url |
https://digitalcommons.usf.edu/msc_facpub/1559 https://doi.org/10.1016/j.geomorph.2015.05.020 |
long_lat |
ENVELOPE(-96.000,-96.000,-72.750,-72.750) |
geographic |
Antarctic West Antarctica Amundsen Sea West Antarctic Ice Sheet Abbot Ice Shelf |
geographic_facet |
Antarctic West Antarctica Amundsen Sea West Antarctic Ice Sheet Abbot Ice Shelf |
genre |
Abbot Ice Shelf Amundsen Sea Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Pine Island West Antarctica |
genre_facet |
Abbot Ice Shelf Amundsen Sea Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Pine Island West Antarctica |
op_source |
Marine Science Faculty Publications |
op_relation |
https://digitalcommons.usf.edu/msc_facpub/1559 https://doi.org/10.1016/j.geomorph.2015.05.020 |
op_doi |
https://doi.org/10.1016/j.geomorph.2015.05.020 |
container_title |
Geomorphology |
container_volume |
245 |
container_start_page |
207 |
op_container_end_page |
222 |
_version_ |
1766379309637828608 |