Large-scale Submarine Landslides, Channel and Gully Systems on the Southern Weddell Sea Margin, Antarctica
New multibeam bathymetric data from the southeastern Weddell Sea show significant differences in surface morphology of the outer continental shelf and slope between two adjacent cross-shelf troughs. These are the Filchner Trough and a smaller trough to the east which we refer to as the ‘Halley Troug...
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Digital Commons @ University of South Florida
2014
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Online Access: | https://digitalcommons.usf.edu/msc_facpub/1554 https://doi.org/10.1016/j.margeo.2013.12.002 |
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ftusouthflorida:oai:digitalcommons.usf.edu:msc_facpub-2556 2023-07-30T03:58:37+02:00 Large-scale Submarine Landslides, Channel and Gully Systems on the Southern Weddell Sea Margin, Antarctica Gales, J. A. Leat, P. T. Larter, R. D. Kuhn, G. Hillenbrand, C.-D. Graham, A. G. C. Mitchell, N. C. Tate, A. J. Buys, G. B. Jokat, W. 2014-01-01T08:00:00Z https://digitalcommons.usf.edu/msc_facpub/1554 https://doi.org/10.1016/j.margeo.2013.12.002 unknown Digital Commons @ University of South Florida https://digitalcommons.usf.edu/msc_facpub/1554 doi:10.1016/j.margeo.2013.12.002 https://doi.org/10.1016/j.margeo.2013.12.002 Marine Science Faculty Publications slope processes Antarctica continental slope slide mass wasting trough mouth fan Life Sciences article 2014 ftusouthflorida https://doi.org/10.1016/j.margeo.2013.12.002 2023-07-13T21:02:30Z New multibeam bathymetric data from the southeastern Weddell Sea show significant differences in surface morphology of the outer continental shelf and slope between two adjacent cross-shelf troughs. These are the Filchner Trough and a smaller trough to the east which we refer to as the ‘Halley Trough’. Multibeam bathymetric data, acoustic sub-bottom profiler and seismic data show major differences in the incidence and morphologies of submarine gullies, channel systems, submarine slides and iceberg scours, and in sediment deposition. These large-scale differences suggest significant variation in slope and sedimentary processes and in the environmental setting between the two troughs, leading to much greater deposition at the mouth of the Filchner Trough. Bedforms, including a terminal moraine and scalloped embayments on the outer shelf of the Halley Trough, provide insight into the relative timing and extent of past ice-sheet grounding and point to grounded ice near to the shelf edge during the Late Quaternary. The new data reveal two large-scale submarine slides on the upper slope of the eastern Crary Fan, a trough mouth fan offshore from the Filchner Trough. Both slides head at the shelf edge (~ 500 m water depth), with the largest slide measuring 20 km wide and with an incision depth of 60 m. Multibeam and seismic data show elongate slabs on the seafloor surface of the mid-slope. The lack of a discernible sedimentary cover suggests that they were generated after the Last Glacial Maximum (LGM). This is unusual because post-LGM submarine slides are very rare on the Antarctic continental margin, and to our knowledge, no other post-LGM slides have been documented on an Antarctic trough mouth fan. Because the slides occur on a part of the continental slope where the deposition of glacial debris was greatest, we speculate that weaker, unconsolidated sedimentary layers within the subsurface are important for slide initiation here. Article in Journal/Newspaper Antarc* Antarctic Antarctica Ice Sheet Iceberg* Weddell Sea University of South Florida St. Petersburg: Digital USFSP Antarctic Filchner Trough ENVELOPE(-36.000,-36.000,-77.000,-77.000) The Antarctic Weddell Weddell Sea Marine Geology 348 73 87 |
institution |
Open Polar |
collection |
University of South Florida St. Petersburg: Digital USFSP |
op_collection_id |
ftusouthflorida |
language |
unknown |
topic |
slope processes Antarctica continental slope slide mass wasting trough mouth fan Life Sciences |
spellingShingle |
slope processes Antarctica continental slope slide mass wasting trough mouth fan Life Sciences Gales, J. A. Leat, P. T. Larter, R. D. Kuhn, G. Hillenbrand, C.-D. Graham, A. G. C. Mitchell, N. C. Tate, A. J. Buys, G. B. Jokat, W. Large-scale Submarine Landslides, Channel and Gully Systems on the Southern Weddell Sea Margin, Antarctica |
topic_facet |
slope processes Antarctica continental slope slide mass wasting trough mouth fan Life Sciences |
description |
New multibeam bathymetric data from the southeastern Weddell Sea show significant differences in surface morphology of the outer continental shelf and slope between two adjacent cross-shelf troughs. These are the Filchner Trough and a smaller trough to the east which we refer to as the ‘Halley Trough’. Multibeam bathymetric data, acoustic sub-bottom profiler and seismic data show major differences in the incidence and morphologies of submarine gullies, channel systems, submarine slides and iceberg scours, and in sediment deposition. These large-scale differences suggest significant variation in slope and sedimentary processes and in the environmental setting between the two troughs, leading to much greater deposition at the mouth of the Filchner Trough. Bedforms, including a terminal moraine and scalloped embayments on the outer shelf of the Halley Trough, provide insight into the relative timing and extent of past ice-sheet grounding and point to grounded ice near to the shelf edge during the Late Quaternary. The new data reveal two large-scale submarine slides on the upper slope of the eastern Crary Fan, a trough mouth fan offshore from the Filchner Trough. Both slides head at the shelf edge (~ 500 m water depth), with the largest slide measuring 20 km wide and with an incision depth of 60 m. Multibeam and seismic data show elongate slabs on the seafloor surface of the mid-slope. The lack of a discernible sedimentary cover suggests that they were generated after the Last Glacial Maximum (LGM). This is unusual because post-LGM submarine slides are very rare on the Antarctic continental margin, and to our knowledge, no other post-LGM slides have been documented on an Antarctic trough mouth fan. Because the slides occur on a part of the continental slope where the deposition of glacial debris was greatest, we speculate that weaker, unconsolidated sedimentary layers within the subsurface are important for slide initiation here. |
format |
Article in Journal/Newspaper |
author |
Gales, J. A. Leat, P. T. Larter, R. D. Kuhn, G. Hillenbrand, C.-D. Graham, A. G. C. Mitchell, N. C. Tate, A. J. Buys, G. B. Jokat, W. |
author_facet |
Gales, J. A. Leat, P. T. Larter, R. D. Kuhn, G. Hillenbrand, C.-D. Graham, A. G. C. Mitchell, N. C. Tate, A. J. Buys, G. B. Jokat, W. |
author_sort |
Gales, J. A. |
title |
Large-scale Submarine Landslides, Channel and Gully Systems on the Southern Weddell Sea Margin, Antarctica |
title_short |
Large-scale Submarine Landslides, Channel and Gully Systems on the Southern Weddell Sea Margin, Antarctica |
title_full |
Large-scale Submarine Landslides, Channel and Gully Systems on the Southern Weddell Sea Margin, Antarctica |
title_fullStr |
Large-scale Submarine Landslides, Channel and Gully Systems on the Southern Weddell Sea Margin, Antarctica |
title_full_unstemmed |
Large-scale Submarine Landslides, Channel and Gully Systems on the Southern Weddell Sea Margin, Antarctica |
title_sort |
large-scale submarine landslides, channel and gully systems on the southern weddell sea margin, antarctica |
publisher |
Digital Commons @ University of South Florida |
publishDate |
2014 |
url |
https://digitalcommons.usf.edu/msc_facpub/1554 https://doi.org/10.1016/j.margeo.2013.12.002 |
long_lat |
ENVELOPE(-36.000,-36.000,-77.000,-77.000) |
geographic |
Antarctic Filchner Trough The Antarctic Weddell Weddell Sea |
geographic_facet |
Antarctic Filchner Trough The Antarctic Weddell Weddell Sea |
genre |
Antarc* Antarctic Antarctica Ice Sheet Iceberg* Weddell Sea |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet Iceberg* Weddell Sea |
op_source |
Marine Science Faculty Publications |
op_relation |
https://digitalcommons.usf.edu/msc_facpub/1554 doi:10.1016/j.margeo.2013.12.002 https://doi.org/10.1016/j.margeo.2013.12.002 |
op_doi |
https://doi.org/10.1016/j.margeo.2013.12.002 |
container_title |
Marine Geology |
container_volume |
348 |
container_start_page |
73 |
op_container_end_page |
87 |
_version_ |
1772821381483855872 |