Processes controlling the formation of the Mertz Drift, George Vth continental shelf, East Antarctica: evidence from 3.5 kHz sub-bottom profiling and sediment cores
Recently discovered sediment drift deposits on the Antarctic continental shelf provide access to information on the Holocene palaeoceanography of the bottom current regime within deep shelf basins that were previously inaccessible. The George Vth Basin on the East Antarctic margin has been identifie...
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ftunivtasecite:oai:ecite.utas.edu.au:28236 2023-05-15T14:03:54+02:00 Processes controlling the formation of the Mertz Drift, George Vth continental shelf, East Antarctica: evidence from 3.5 kHz sub-bottom profiling and sediment cores Harris, PT Beaman, RJ 2003 https://doi.org/10.1016/S0967-0645(03)00070-5 http://ecite.utas.edu.au/28236 en eng Pergamon-Elsevier Science Ltd http://dx.doi.org/10.1016/S0967-0645(03)00070-5 Harris, PT and Beaman, RJ, Processes controlling the formation of the Mertz Drift, George Vth continental shelf, East Antarctica: evidence from 3.5 kHz sub-bottom profiling and sediment cores, Deep Sea Research Part II: Topical Studies in Oceanography, 50, (8-9) pp. 1463-1480. ISSN 0967-0645 (2003) [Refereed Article] http://ecite.utas.edu.au/28236 Earth Sciences Oceanography Physical Oceanography Refereed Article PeerReviewed 2003 ftunivtasecite https://doi.org/10.1016/S0967-0645(03)00070-5 2019-12-13T21:08:46Z Recently discovered sediment drift deposits on the Antarctic continental shelf provide access to information on the Holocene palaeoceanography of the bottom current regime within deep shelf basins that were previously inaccessible. The George Vth Basin on the East Antarctic margin has been identified by oceanographers as an important source of Antarctic Bottom Water, hence the Holocene history of bottom current activity here may be relevant to variations in bottom water export. The analysis of seismic and sediment core data indicates that the Holocene history of sedimentation on the Mertz Drift occurred in response to a progressively changing bottom current regime. The stratigraphic horizons that mark the onset of different phases of deposition are diachronous within the Mertz Drift. Rapidly accumulating, laminated siliceous mud and diatom ooze (SMO) that comprises the bulk was deposited first on the eastern side of the drift (5000-3500 years BP) and later on the lobate, southwestern side (3000 and 2000 years BP). This spatial variation in timing of rapid SMO deposition is attributed to a gradual increase in bottom current speed over the mid- to late Holocene. The deposition of true drift-style sedimentary features is restricted to a small area in the southwestern corner of the Mertz Drift, with the remaining parts characterised by drape and fill deposits. An estimation of the mass flux of sediment reaching the drift suggests that the modern, stronger bottom currents need carry only a very low suspended sediment concentration to explain the measured 10-fold reduction in sediment accumulation rates after 3000 years BP. Cores from the Mertz Drift and from a perched basin located 60 km to the east contain the same lithologic units and have the same approximate age. Thus the palaeoenvironmental interpretations based on the Mertz Drift can be extrapolated over the entire George Vth Basin region. Crown Copyright 2003 Published by Elsevier Science Ltd. All rights reserved. Article in Journal/Newspaper Antarc* Antarctic Antarctica East Antarctica eCite UTAS (University of Tasmania) Antarctic East Antarctica The Antarctic Deep Sea Research Part II: Topical Studies in Oceanography 50 8-9 1463 1480 |
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 Harris, PT Beaman, RJ Processes controlling the formation of the Mertz Drift, George Vth continental shelf, East Antarctica: evidence from 3.5 kHz sub-bottom profiling and sediment cores |
topic_facet |
Earth Sciences Oceanography Physical Oceanography |
description |
Recently discovered sediment drift deposits on the Antarctic continental shelf provide access to information on the Holocene palaeoceanography of the bottom current regime within deep shelf basins that were previously inaccessible. The George Vth Basin on the East Antarctic margin has been identified by oceanographers as an important source of Antarctic Bottom Water, hence the Holocene history of bottom current activity here may be relevant to variations in bottom water export. The analysis of seismic and sediment core data indicates that the Holocene history of sedimentation on the Mertz Drift occurred in response to a progressively changing bottom current regime. The stratigraphic horizons that mark the onset of different phases of deposition are diachronous within the Mertz Drift. Rapidly accumulating, laminated siliceous mud and diatom ooze (SMO) that comprises the bulk was deposited first on the eastern side of the drift (5000-3500 years BP) and later on the lobate, southwestern side (3000 and 2000 years BP). This spatial variation in timing of rapid SMO deposition is attributed to a gradual increase in bottom current speed over the mid- to late Holocene. The deposition of true drift-style sedimentary features is restricted to a small area in the southwestern corner of the Mertz Drift, with the remaining parts characterised by drape and fill deposits. An estimation of the mass flux of sediment reaching the drift suggests that the modern, stronger bottom currents need carry only a very low suspended sediment concentration to explain the measured 10-fold reduction in sediment accumulation rates after 3000 years BP. Cores from the Mertz Drift and from a perched basin located 60 km to the east contain the same lithologic units and have the same approximate age. Thus the palaeoenvironmental interpretations based on the Mertz Drift can be extrapolated over the entire George Vth Basin region. Crown Copyright 2003 Published by Elsevier Science Ltd. All rights reserved. |
format |
Article in Journal/Newspaper |
author |
Harris, PT Beaman, RJ |
author_facet |
Harris, PT Beaman, RJ |
author_sort |
Harris, PT |
title |
Processes controlling the formation of the Mertz Drift, George Vth continental shelf, East Antarctica: evidence from 3.5 kHz sub-bottom profiling and sediment cores |
title_short |
Processes controlling the formation of the Mertz Drift, George Vth continental shelf, East Antarctica: evidence from 3.5 kHz sub-bottom profiling and sediment cores |
title_full |
Processes controlling the formation of the Mertz Drift, George Vth continental shelf, East Antarctica: evidence from 3.5 kHz sub-bottom profiling and sediment cores |
title_fullStr |
Processes controlling the formation of the Mertz Drift, George Vth continental shelf, East Antarctica: evidence from 3.5 kHz sub-bottom profiling and sediment cores |
title_full_unstemmed |
Processes controlling the formation of the Mertz Drift, George Vth continental shelf, East Antarctica: evidence from 3.5 kHz sub-bottom profiling and sediment cores |
title_sort |
processes controlling the formation of the mertz drift, george vth continental shelf, east antarctica: evidence from 3.5 khz sub-bottom profiling and sediment cores |
publisher |
Pergamon-Elsevier Science Ltd |
publishDate |
2003 |
url |
https://doi.org/10.1016/S0967-0645(03)00070-5 http://ecite.utas.edu.au/28236 |
geographic |
Antarctic East Antarctica The Antarctic |
geographic_facet |
Antarctic East Antarctica The Antarctic |
genre |
Antarc* Antarctic Antarctica East Antarctica |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica |
op_relation |
http://dx.doi.org/10.1016/S0967-0645(03)00070-5 Harris, PT and Beaman, RJ, Processes controlling the formation of the Mertz Drift, George Vth continental shelf, East Antarctica: evidence from 3.5 kHz sub-bottom profiling and sediment cores, Deep Sea Research Part II: Topical Studies in Oceanography, 50, (8-9) pp. 1463-1480. ISSN 0967-0645 (2003) [Refereed Article] http://ecite.utas.edu.au/28236 |
op_doi |
https://doi.org/10.1016/S0967-0645(03)00070-5 |
container_title |
Deep Sea Research Part II: Topical Studies in Oceanography |
container_volume |
50 |
container_issue |
8-9 |
container_start_page |
1463 |
op_container_end_page |
1480 |
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