Sedimentological signatures of the sub-Amery Ice Shelf circulation
Two sediment cores collected from beneath the Amery Ice Shelf, East Antarctica describe the physical sedimentation patterns beneath an existing major embayed ice shelf. Core AM01b was collected from a site of basal freezing, contrasting with core AM02, collected from a site of basal melting. Both co...
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Online Access: | https://doi.org/10.1017/S0954102007000697 http://ecite.utas.edu.au/50240 |
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ftunivtasecite:oai:ecite.utas.edu.au:50240 2023-05-15T13:22:00+02:00 Sedimentological signatures of the sub-Amery Ice Shelf circulation Hemer, MA Post, AL O'Brien, PE Craven, M Truswell, EM Roberts, D Harris, PT 2007 https://doi.org/10.1017/S0954102007000697 http://ecite.utas.edu.au/50240 en eng Cambridge University Press http://dx.doi.org/10.1017/S0954102007000697 Hemer, MA and Post, AL and O'Brien, PE and Craven, M and Truswell, EM and Roberts, D and Harris, PT, Sedimentological signatures of the sub-Amery Ice Shelf circulation, Antarctic Science, 19, (4) pp. 497-506. ISSN 0954-1020 (2007) [Refereed Article] http://ecite.utas.edu.au/50240 Earth Sciences Oceanography Physical Oceanography Refereed Article PeerReviewed 2007 ftunivtasecite https://doi.org/10.1017/S0954102007000697 2019-12-13T21:24:38Z Two sediment cores collected from beneath the Amery Ice Shelf, East Antarctica describe the physical sedimentation patterns beneath an existing major embayed ice shelf. Core AM01b was collected from a site of basal freezing, contrasting with core AM02, collected from a site of basal melting. Both cores comprise Holocene siliceous muddy ooze (SMO), however, AM01b also recovered interbedded siliciclastic mud, sand and gravel with inclined bedding in its lower 27 cm. This interval indicates an episode of variable but strong current activity before SMO sedimentation became dominant. 14C ages corrected for old surface ages are consistent with previous dating of marine sediments in Prydz Bay. However, the basal age of AM01b of 28250 230 14C yr bp probably results from greater contamination by recycled organic matter. Lithology, 14C surface ages, absolute diatom abundance, and the diatom assemblage are used as indicators of sediment transport pathways beneath the ice shelf. The transport pathways suggested from these indicators do not correspond to previous models of the basal melt/freeze pattern. This indicates that the overturning baroclinic circulation beneath the Amery Ice Shelf (near-bed inflowsurface outflow) is a more important influence on basal melt/freeze and sediment distributions than the barotropic circulation that produces inflow in the east and outflow in the west of the ice front. Localized topographic (ice draft and bed elevation) variations are likely to play a dominant role in the resulting sub-ice shelf melt and sediment distribution. Article in Journal/Newspaper Amery Ice Shelf Antarc* Antarctic Science Antarctica East Antarctica Ice Shelf Prydz Bay eCite UTAS (University of Tasmania) East Antarctica Prydz Bay Amery ENVELOPE(-94.063,-94.063,56.565,56.565) Amery Ice Shelf ENVELOPE(71.000,71.000,-69.750,-69.750) Antarctic Science 19 4 497 506 |
institution |
Open Polar |
collection |
eCite UTAS (University of Tasmania) |
op_collection_id |
ftunivtasecite |
language |
English |
topic |
Earth Sciences Oceanography Physical Oceanography |
spellingShingle |
Earth Sciences Oceanography Physical Oceanography Hemer, MA Post, AL O'Brien, PE Craven, M Truswell, EM Roberts, D Harris, PT Sedimentological signatures of the sub-Amery Ice Shelf circulation |
topic_facet |
Earth Sciences Oceanography Physical Oceanography |
description |
Two sediment cores collected from beneath the Amery Ice Shelf, East Antarctica describe the physical sedimentation patterns beneath an existing major embayed ice shelf. Core AM01b was collected from a site of basal freezing, contrasting with core AM02, collected from a site of basal melting. Both cores comprise Holocene siliceous muddy ooze (SMO), however, AM01b also recovered interbedded siliciclastic mud, sand and gravel with inclined bedding in its lower 27 cm. This interval indicates an episode of variable but strong current activity before SMO sedimentation became dominant. 14C ages corrected for old surface ages are consistent with previous dating of marine sediments in Prydz Bay. However, the basal age of AM01b of 28250 230 14C yr bp probably results from greater contamination by recycled organic matter. Lithology, 14C surface ages, absolute diatom abundance, and the diatom assemblage are used as indicators of sediment transport pathways beneath the ice shelf. The transport pathways suggested from these indicators do not correspond to previous models of the basal melt/freeze pattern. This indicates that the overturning baroclinic circulation beneath the Amery Ice Shelf (near-bed inflowsurface outflow) is a more important influence on basal melt/freeze and sediment distributions than the barotropic circulation that produces inflow in the east and outflow in the west of the ice front. Localized topographic (ice draft and bed elevation) variations are likely to play a dominant role in the resulting sub-ice shelf melt and sediment distribution. |
format |
Article in Journal/Newspaper |
author |
Hemer, MA Post, AL O'Brien, PE Craven, M Truswell, EM Roberts, D Harris, PT |
author_facet |
Hemer, MA Post, AL O'Brien, PE Craven, M Truswell, EM Roberts, D Harris, PT |
author_sort |
Hemer, MA |
title |
Sedimentological signatures of the sub-Amery Ice Shelf circulation |
title_short |
Sedimentological signatures of the sub-Amery Ice Shelf circulation |
title_full |
Sedimentological signatures of the sub-Amery Ice Shelf circulation |
title_fullStr |
Sedimentological signatures of the sub-Amery Ice Shelf circulation |
title_full_unstemmed |
Sedimentological signatures of the sub-Amery Ice Shelf circulation |
title_sort |
sedimentological signatures of the sub-amery ice shelf circulation |
publisher |
Cambridge University Press |
publishDate |
2007 |
url |
https://doi.org/10.1017/S0954102007000697 http://ecite.utas.edu.au/50240 |
long_lat |
ENVELOPE(-94.063,-94.063,56.565,56.565) ENVELOPE(71.000,71.000,-69.750,-69.750) |
geographic |
East Antarctica Prydz Bay Amery Amery Ice Shelf |
geographic_facet |
East Antarctica Prydz Bay Amery Amery Ice Shelf |
genre |
Amery Ice Shelf Antarc* Antarctic Science Antarctica East Antarctica Ice Shelf Prydz Bay |
genre_facet |
Amery Ice Shelf Antarc* Antarctic Science Antarctica East Antarctica Ice Shelf Prydz Bay |
op_relation |
http://dx.doi.org/10.1017/S0954102007000697 Hemer, MA and Post, AL and O'Brien, PE and Craven, M and Truswell, EM and Roberts, D and Harris, PT, Sedimentological signatures of the sub-Amery Ice Shelf circulation, Antarctic Science, 19, (4) pp. 497-506. ISSN 0954-1020 (2007) [Refereed Article] http://ecite.utas.edu.au/50240 |
op_doi |
https://doi.org/10.1017/S0954102007000697 |
container_title |
Antarctic Science |
container_volume |
19 |
container_issue |
4 |
container_start_page |
497 |
op_container_end_page |
506 |
_version_ |
1766362744924143616 |