Upper slope processes and seafloor ecosystems on the Sabrina continental slope, East Antarctica
This study applies detailed seafloor bathymetry data and seafloor images to understand upper slope features and how these influence the distribution of seafloor biota on the East Antarctic margin. The East Antarctic slope on the Sabrina margin has been shaped by diverse processes related to repeated...
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ftanucanberra:oai:openresearch-repository.anu.edu.au:1885/219025 2024-01-14T10:01:38+01:00 Upper slope processes and seafloor ecosystems on the Sabrina continental slope, East Antarctica Post, A. O'Brien, P. E. Edwards, S. Carroll, A. G. Malakof, K. Armand, Leanne application/pdf http://hdl.handle.net/1885/219025 https://doi.org/10.1016/j.margeo.2019.106091 https://openresearch-repository.anu.edu.au/bitstream/1885/219025/3/01_Post_Upper_slope_processes_and_2020.pdf.jpg en_AU eng Elsevier 0025-3227 http://hdl.handle.net/1885/219025 doi:10.1016/j.margeo.2019.106091 https://openresearch-repository.anu.edu.au/bitstream/1885/219025/3/01_Post_Upper_slope_processes_and_2020.pdf.jpg © 2019 Crown Copyright Marine Geology Continental margin morphology Southern Ocean Multibeam bathymetry Benthic biota Biodiversity Journal article ftanucanberra https://doi.org/10.1016/j.margeo.2019.106091 2023-12-15T09:34:45Z This study applies detailed seafloor bathymetry data and seafloor images to understand upper slope features and how these influence the distribution of seafloor biota on the East Antarctic margin. The East Antarctic slope on the Sabrina margin has been shaped by diverse processes related to repeated glaciation. Differences in the morphology of gullies on the upper slope enable an understanding of the likely processes that have been active on this margin. Gully morphology varies according to changes in slope gradient, which may have driven variations in sedimentation. Areas of lower slope angles may have led to rapid sediment deposition during glacial expansion to the shelf edge, and subsequent sediment failure. Typically, gullies in these areas are U-shaped, initiate well below the shelf break, are relatively straight and long, and have low incision depths, consistent with formation due to mass wastage. Areas of higher slope angles likely experienced enhanced flow of erosive turbidity currents during glaciations associated with the release of sediment-laden basal meltwaters. Sediment-laden subglacial meltwater flows typically create gullies such as those we observe that initiate at, or near, the shelf break; are V-shaped in profile; and have high sinuosity, deep incision depths and a relatively short downslope extent. The short downslope extent reflects a reduced sediment load associated with increased seawater entrainment as the slope becomes more concave in profile. These differences in gully morphology have important habitat implications associated with differences in the composition and beta-diversity of the seafloor communities. This upper slope region also supports seafloor communities that are distinct from those on the adjacent shelf, highlighting the uniqueness of this environment for biodiversity. Conservation strategies therefore need to consider slope and shelf communities as distinct and equally important components of the Antarctic ecosystem. This project is supported through funding from the ... Article in Journal/Newspaper Antarc* Antarctic Antarctica East Antarctica Southern Ocean Australian National University: ANU Digital Collections Antarctic Southern Ocean The Antarctic East Antarctica Marine Geology 422 106091 |
institution |
Open Polar |
collection |
Australian National University: ANU Digital Collections |
op_collection_id |
ftanucanberra |
language |
English |
topic |
Continental margin morphology Southern Ocean Multibeam bathymetry Benthic biota Biodiversity |
spellingShingle |
Continental margin morphology Southern Ocean Multibeam bathymetry Benthic biota Biodiversity Post, A. O'Brien, P. E. Edwards, S. Carroll, A. G. Malakof, K. Armand, Leanne Upper slope processes and seafloor ecosystems on the Sabrina continental slope, East Antarctica |
topic_facet |
Continental margin morphology Southern Ocean Multibeam bathymetry Benthic biota Biodiversity |
description |
This study applies detailed seafloor bathymetry data and seafloor images to understand upper slope features and how these influence the distribution of seafloor biota on the East Antarctic margin. The East Antarctic slope on the Sabrina margin has been shaped by diverse processes related to repeated glaciation. Differences in the morphology of gullies on the upper slope enable an understanding of the likely processes that have been active on this margin. Gully morphology varies according to changes in slope gradient, which may have driven variations in sedimentation. Areas of lower slope angles may have led to rapid sediment deposition during glacial expansion to the shelf edge, and subsequent sediment failure. Typically, gullies in these areas are U-shaped, initiate well below the shelf break, are relatively straight and long, and have low incision depths, consistent with formation due to mass wastage. Areas of higher slope angles likely experienced enhanced flow of erosive turbidity currents during glaciations associated with the release of sediment-laden basal meltwaters. Sediment-laden subglacial meltwater flows typically create gullies such as those we observe that initiate at, or near, the shelf break; are V-shaped in profile; and have high sinuosity, deep incision depths and a relatively short downslope extent. The short downslope extent reflects a reduced sediment load associated with increased seawater entrainment as the slope becomes more concave in profile. These differences in gully morphology have important habitat implications associated with differences in the composition and beta-diversity of the seafloor communities. This upper slope region also supports seafloor communities that are distinct from those on the adjacent shelf, highlighting the uniqueness of this environment for biodiversity. Conservation strategies therefore need to consider slope and shelf communities as distinct and equally important components of the Antarctic ecosystem. This project is supported through funding from the ... |
format |
Article in Journal/Newspaper |
author |
Post, A. O'Brien, P. E. Edwards, S. Carroll, A. G. Malakof, K. Armand, Leanne |
author_facet |
Post, A. O'Brien, P. E. Edwards, S. Carroll, A. G. Malakof, K. Armand, Leanne |
author_sort |
Post, A. |
title |
Upper slope processes and seafloor ecosystems on the Sabrina continental slope, East Antarctica |
title_short |
Upper slope processes and seafloor ecosystems on the Sabrina continental slope, East Antarctica |
title_full |
Upper slope processes and seafloor ecosystems on the Sabrina continental slope, East Antarctica |
title_fullStr |
Upper slope processes and seafloor ecosystems on the Sabrina continental slope, East Antarctica |
title_full_unstemmed |
Upper slope processes and seafloor ecosystems on the Sabrina continental slope, East Antarctica |
title_sort |
upper slope processes and seafloor ecosystems on the sabrina continental slope, east antarctica |
publisher |
Elsevier |
url |
http://hdl.handle.net/1885/219025 https://doi.org/10.1016/j.margeo.2019.106091 https://openresearch-repository.anu.edu.au/bitstream/1885/219025/3/01_Post_Upper_slope_processes_and_2020.pdf.jpg |
geographic |
Antarctic Southern Ocean The Antarctic East Antarctica |
geographic_facet |
Antarctic Southern Ocean The Antarctic East Antarctica |
genre |
Antarc* Antarctic Antarctica East Antarctica Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica Southern Ocean |
op_source |
Marine Geology |
op_relation |
0025-3227 http://hdl.handle.net/1885/219025 doi:10.1016/j.margeo.2019.106091 https://openresearch-repository.anu.edu.au/bitstream/1885/219025/3/01_Post_Upper_slope_processes_and_2020.pdf.jpg |
op_rights |
© 2019 Crown Copyright |
op_doi |
https://doi.org/10.1016/j.margeo.2019.106091 |
container_title |
Marine Geology |
container_volume |
422 |
container_start_page |
106091 |
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1788067385816645632 |