Bedform Signature of a West Antarctic Palaeo-ice Stream Reveals a Multi-temporal Record of Flow and Substrate Control
The presence of a complex bedform arrangement on the sea floor of the continental shelf in the western Amundsen Sea Embayment, West Antarctica, indicates a multi-temporal record of flow related to the activity of one or more ice streams in the past. Mapping and division of the bedforms into distinct...
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ftunisfloridatam:oai:digitalcommons.usf.edu:msc_facpub-2576 2023-05-15T13:24:14+02:00 Bedform Signature of a West Antarctic Palaeo-ice Stream Reveals a Multi-temporal Record of Flow and Substrate Control Graham, Alastair G. C. Larter, Robert D. Gohl, Karsten Hillenbrand, Claus-Dieter Smith, James A. Kuhn, Gerhard 2009-01-01T08:00:00Z https://digitalcommons.usf.edu/msc_facpub/1536 https://doi.org/10.1016/j.quascirev.2009.07.003 unknown Digital Commons @ University of South Florida https://digitalcommons.usf.edu/msc_facpub/1536 https://doi.org/10.1016/j.quascirev.2009.07.003 Marine Science Faculty Publications Life Sciences article 2009 ftunisfloridatam https://doi.org/10.1016/j.quascirev.2009.07.003 2022-01-20T18:39:16Z The presence of a complex bedform arrangement on the sea floor of the continental shelf in the western Amundsen Sea Embayment, West Antarctica, indicates a multi-temporal record of flow related to the activity of one or more ice streams in the past. Mapping and division of the bedforms into distinct landform assemblages reveals their time-transgressive history, which implies that bedforms can neither be considered part of a single downflow continuum nor a direct proxy for palaeo-ice velocity, as suggested previously. A main control on the bedform imprint is the geology of the shelf, which is divided broadly between rough bedrock on the inner shelf, and smooth, dipping sedimentary strata on the middle to outer shelf. Inner shelf bedform variability is well preserved, revealing information about local, complex basal ice conditions, meltwater flow, and ice dynamics over time. These details, which are not apparent at the scale of regional morphological studies, indicate that past ice streams flowed across the entire shelf at times, and often had onset zones that lay within the interior of the Antarctic Ice Sheet today. In contrast, highly elongated subglacial bedforms on sedimentary strata of the middle to outer shelf represent a timeslice snapshot of the last activity of ice stream flow, and may be a truer representation of fast palaeo-ice flow in these locations. A revised model for ice streams on the shelf captures complicated multi-temporal bedform patterns associated with an Antarctic palaeo-ice stream for the first time, and confirms a strong substrate control on a major ice stream system that drained the West Antarctic Ice Sheet during the Late Quaternary. Article in Journal/Newspaper Amundsen Sea Antarc* Antarctic Antarctica Ice Sheet West Antarctica Digital Commons University of South Florida (USF) Antarctic The Antarctic West Antarctica Amundsen Sea West Antarctic Ice Sheet Quaternary Science Reviews 28 25-26 2774 2793 |
institution |
Open Polar |
collection |
Digital Commons University of South Florida (USF) |
op_collection_id |
ftunisfloridatam |
language |
unknown |
topic |
Life Sciences |
spellingShingle |
Life Sciences Graham, Alastair G. C. Larter, Robert D. Gohl, Karsten Hillenbrand, Claus-Dieter Smith, James A. Kuhn, Gerhard Bedform Signature of a West Antarctic Palaeo-ice Stream Reveals a Multi-temporal Record of Flow and Substrate Control |
topic_facet |
Life Sciences |
description |
The presence of a complex bedform arrangement on the sea floor of the continental shelf in the western Amundsen Sea Embayment, West Antarctica, indicates a multi-temporal record of flow related to the activity of one or more ice streams in the past. Mapping and division of the bedforms into distinct landform assemblages reveals their time-transgressive history, which implies that bedforms can neither be considered part of a single downflow continuum nor a direct proxy for palaeo-ice velocity, as suggested previously. A main control on the bedform imprint is the geology of the shelf, which is divided broadly between rough bedrock on the inner shelf, and smooth, dipping sedimentary strata on the middle to outer shelf. Inner shelf bedform variability is well preserved, revealing information about local, complex basal ice conditions, meltwater flow, and ice dynamics over time. These details, which are not apparent at the scale of regional morphological studies, indicate that past ice streams flowed across the entire shelf at times, and often had onset zones that lay within the interior of the Antarctic Ice Sheet today. In contrast, highly elongated subglacial bedforms on sedimentary strata of the middle to outer shelf represent a timeslice snapshot of the last activity of ice stream flow, and may be a truer representation of fast palaeo-ice flow in these locations. A revised model for ice streams on the shelf captures complicated multi-temporal bedform patterns associated with an Antarctic palaeo-ice stream for the first time, and confirms a strong substrate control on a major ice stream system that drained the West Antarctic Ice Sheet during the Late Quaternary. |
format |
Article in Journal/Newspaper |
author |
Graham, Alastair G. C. Larter, Robert D. Gohl, Karsten Hillenbrand, Claus-Dieter Smith, James A. Kuhn, Gerhard |
author_facet |
Graham, Alastair G. C. Larter, Robert D. Gohl, Karsten Hillenbrand, Claus-Dieter Smith, James A. Kuhn, Gerhard |
author_sort |
Graham, Alastair G. C. |
title |
Bedform Signature of a West Antarctic Palaeo-ice Stream Reveals a Multi-temporal Record of Flow and Substrate Control |
title_short |
Bedform Signature of a West Antarctic Palaeo-ice Stream Reveals a Multi-temporal Record of Flow and Substrate Control |
title_full |
Bedform Signature of a West Antarctic Palaeo-ice Stream Reveals a Multi-temporal Record of Flow and Substrate Control |
title_fullStr |
Bedform Signature of a West Antarctic Palaeo-ice Stream Reveals a Multi-temporal Record of Flow and Substrate Control |
title_full_unstemmed |
Bedform Signature of a West Antarctic Palaeo-ice Stream Reveals a Multi-temporal Record of Flow and Substrate Control |
title_sort |
bedform signature of a west antarctic palaeo-ice stream reveals a multi-temporal record of flow and substrate control |
publisher |
Digital Commons @ University of South Florida |
publishDate |
2009 |
url |
https://digitalcommons.usf.edu/msc_facpub/1536 https://doi.org/10.1016/j.quascirev.2009.07.003 |
geographic |
Antarctic The Antarctic West Antarctica Amundsen Sea West Antarctic Ice Sheet |
geographic_facet |
Antarctic The Antarctic West Antarctica Amundsen Sea West Antarctic Ice Sheet |
genre |
Amundsen Sea Antarc* Antarctic Antarctica Ice Sheet West Antarctica |
genre_facet |
Amundsen Sea Antarc* Antarctic Antarctica Ice Sheet West Antarctica |
op_source |
Marine Science Faculty Publications |
op_relation |
https://digitalcommons.usf.edu/msc_facpub/1536 https://doi.org/10.1016/j.quascirev.2009.07.003 |
op_doi |
https://doi.org/10.1016/j.quascirev.2009.07.003 |
container_title |
Quaternary Science Reviews |
container_volume |
28 |
container_issue |
25-26 |
container_start_page |
2774 |
op_container_end_page |
2793 |
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1766378196402438144 |