Absence of a strong, deep-reaching Antarctic Circumpolar Current zonal flow across the Tasmanian gateway during the Oligocene to early Miocene
The vigorous eastward flow of the Antarctic Circumpolar Current (ACC) connects all major ocean basins and plays a prominent role in the transport of heat, carbon and nutrients around the globe. However, the establishment of a deep circumpolar flow, similar to the present-day ACC, remains controversi...
Published in: | Global and Planetary Change |
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Language: | English |
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Online Access: | http://hdl.handle.net/10044/1/95072 https://doi.org/10.1016/j.gloplacha.2021.103718 |
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ftimperialcol:oai:spiral.imperial.ac.uk:10044/1/95072 2023-05-15T13:47:47+02:00 Absence of a strong, deep-reaching Antarctic Circumpolar Current zonal flow across the Tasmanian gateway during the Oligocene to early Miocene Evangelinos, D Escutia, C Van de Flierdt, T Valero, L Flores, J-A Harwood, DM Hoem, FS Bijl, P Etourneau, J Kreissig, K Nilsson-Kerr, K Holder, L Lopez-Quiros, A Salabarnada, A 2021-11-26 http://hdl.handle.net/10044/1/95072 https://doi.org/10.1016/j.gloplacha.2021.103718 English eng Elsevier Global and Planetary Change 0921-8181 http://hdl.handle.net/10044/1/95072 doi:10.1016/j.gloplacha.2021.103718 © 2021 Elsevier Ltd. All rights reserved. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Licence http://creativecommons.org/licenses/by-nc-nd/4.0/ http://creativecommons.org/licenses/by-nc-nd/4.0/ CC-BY-NC-ND 12 1 Science & Technology Physical Sciences Geography Physical Geosciences Multidisciplinary Physical Geography Geology ACC CDW Neodymium isotope ratios Deep ocean circulation Tasmanian Gateway Oligocene-early Miocene ICE-SHEET VARIABILITY OFFSHORE WILKES LAND RARE-EARTH-ELEMENTS SOUTHERN-OCEAN CIRCULATION ND ISOTOPIC STRUCTURE ROSS SEA INDIAN-OCEAN NEODYMIUM EOCENE SEAWATER Networking & Telecommunications 04 Earth Sciences Journal Article 2021 ftimperialcol https://doi.org/10.1016/j.gloplacha.2021.103718 2022-12-15T23:42:13Z The vigorous eastward flow of the Antarctic Circumpolar Current (ACC) connects all major ocean basins and plays a prominent role in the transport of heat, carbon and nutrients around the globe. However, the establishment of a deep circumpolar flow, similar to the present-day ACC, remains controversial thereby obscuring our understanding of its climatic impact. Deciphering the chemical composition of Circumpolar Deep Water (CDW) within the ACC can provide critical insights about its development and evolution. Here we present new fossil fish teeth/bone debris neodymium isotope (εNd) records from Deep Sea Drilling Project (DSDP) Sites 278 and 274 in the southwest Pacific Ocean, with the aim to trace changes in deep water masses across the Tasmanian Gateway between the early Oligocene and early Miocene (~ 33–22 Ma). Site 274 provides the first Nd isotope record proximal to the Ross Sea during the Oligocene (33.5–23.4 Ma). Its Nd isotope composition shows excursions to very radiogenic values, εNd(t) = −3.1 and εNd(t)= − 3.7, at 33.5 Ma and 23.8 Ma, respectively, in response to major steps in Antarctic ice sheet expansion. A shift to lower, more unradiogenic εNd(t) values between 29.7 and 29.1 Ma is linked to an increased influence of proto-CDW upwelling at the site. In contrast, the Nd isotope record from Site 278 in the southern Emerald Basin shows little variability (εNd(t) = −6.0 to −6.7) throughout the Oligocene and early Miocene (30.9–21.8 Ma). Comparison with published data north of the ACC path, demonstrates the presence of two deep water masses in the South Pacific prior to the inferred onset of the ACC (33–30 Ma), one occupying depths between ~2500 and 3000 m (εNd(t)= ~ −3 to −5) and a deep/bottom water mass (> 3000 m) with a more unradiogenic Nd isotope composition (εNd(t)= ~ −6). Site 278 located close to the proto-polar front (proto-PF) indicates that following the inferred onset of the ACC, deep waters bathing the southern Emerald Basin remained more radiogenic in the Southwest Pacific compared to ... Article in Journal/Newspaper Antarc* Antarctic Ice Sheet Ross Sea Southern Ocean Wilkes Land Imperial College London: Spiral Antarctic Emerald Basin ENVELOPE(162.500,162.500,-54.000,-54.000) Indian Pacific Ross Sea Southern Ocean The Antarctic Wilkes Land ENVELOPE(120.000,120.000,-69.000,-69.000) Global and Planetary Change 208 103718 |
institution |
Open Polar |
collection |
Imperial College London: Spiral |
op_collection_id |
ftimperialcol |
language |
English |
topic |
Science & Technology Physical Sciences Geography Physical Geosciences Multidisciplinary Physical Geography Geology ACC CDW Neodymium isotope ratios Deep ocean circulation Tasmanian Gateway Oligocene-early Miocene ICE-SHEET VARIABILITY OFFSHORE WILKES LAND RARE-EARTH-ELEMENTS SOUTHERN-OCEAN CIRCULATION ND ISOTOPIC STRUCTURE ROSS SEA INDIAN-OCEAN NEODYMIUM EOCENE SEAWATER Networking & Telecommunications 04 Earth Sciences |
spellingShingle |
Science & Technology Physical Sciences Geography Physical Geosciences Multidisciplinary Physical Geography Geology ACC CDW Neodymium isotope ratios Deep ocean circulation Tasmanian Gateway Oligocene-early Miocene ICE-SHEET VARIABILITY OFFSHORE WILKES LAND RARE-EARTH-ELEMENTS SOUTHERN-OCEAN CIRCULATION ND ISOTOPIC STRUCTURE ROSS SEA INDIAN-OCEAN NEODYMIUM EOCENE SEAWATER Networking & Telecommunications 04 Earth Sciences Evangelinos, D Escutia, C Van de Flierdt, T Valero, L Flores, J-A Harwood, DM Hoem, FS Bijl, P Etourneau, J Kreissig, K Nilsson-Kerr, K Holder, L Lopez-Quiros, A Salabarnada, A Absence of a strong, deep-reaching Antarctic Circumpolar Current zonal flow across the Tasmanian gateway during the Oligocene to early Miocene |
topic_facet |
Science & Technology Physical Sciences Geography Physical Geosciences Multidisciplinary Physical Geography Geology ACC CDW Neodymium isotope ratios Deep ocean circulation Tasmanian Gateway Oligocene-early Miocene ICE-SHEET VARIABILITY OFFSHORE WILKES LAND RARE-EARTH-ELEMENTS SOUTHERN-OCEAN CIRCULATION ND ISOTOPIC STRUCTURE ROSS SEA INDIAN-OCEAN NEODYMIUM EOCENE SEAWATER Networking & Telecommunications 04 Earth Sciences |
description |
The vigorous eastward flow of the Antarctic Circumpolar Current (ACC) connects all major ocean basins and plays a prominent role in the transport of heat, carbon and nutrients around the globe. However, the establishment of a deep circumpolar flow, similar to the present-day ACC, remains controversial thereby obscuring our understanding of its climatic impact. Deciphering the chemical composition of Circumpolar Deep Water (CDW) within the ACC can provide critical insights about its development and evolution. Here we present new fossil fish teeth/bone debris neodymium isotope (εNd) records from Deep Sea Drilling Project (DSDP) Sites 278 and 274 in the southwest Pacific Ocean, with the aim to trace changes in deep water masses across the Tasmanian Gateway between the early Oligocene and early Miocene (~ 33–22 Ma). Site 274 provides the first Nd isotope record proximal to the Ross Sea during the Oligocene (33.5–23.4 Ma). Its Nd isotope composition shows excursions to very radiogenic values, εNd(t) = −3.1 and εNd(t)= − 3.7, at 33.5 Ma and 23.8 Ma, respectively, in response to major steps in Antarctic ice sheet expansion. A shift to lower, more unradiogenic εNd(t) values between 29.7 and 29.1 Ma is linked to an increased influence of proto-CDW upwelling at the site. In contrast, the Nd isotope record from Site 278 in the southern Emerald Basin shows little variability (εNd(t) = −6.0 to −6.7) throughout the Oligocene and early Miocene (30.9–21.8 Ma). Comparison with published data north of the ACC path, demonstrates the presence of two deep water masses in the South Pacific prior to the inferred onset of the ACC (33–30 Ma), one occupying depths between ~2500 and 3000 m (εNd(t)= ~ −3 to −5) and a deep/bottom water mass (> 3000 m) with a more unradiogenic Nd isotope composition (εNd(t)= ~ −6). Site 278 located close to the proto-polar front (proto-PF) indicates that following the inferred onset of the ACC, deep waters bathing the southern Emerald Basin remained more radiogenic in the Southwest Pacific compared to ... |
format |
Article in Journal/Newspaper |
author |
Evangelinos, D Escutia, C Van de Flierdt, T Valero, L Flores, J-A Harwood, DM Hoem, FS Bijl, P Etourneau, J Kreissig, K Nilsson-Kerr, K Holder, L Lopez-Quiros, A Salabarnada, A |
author_facet |
Evangelinos, D Escutia, C Van de Flierdt, T Valero, L Flores, J-A Harwood, DM Hoem, FS Bijl, P Etourneau, J Kreissig, K Nilsson-Kerr, K Holder, L Lopez-Quiros, A Salabarnada, A |
author_sort |
Evangelinos, D |
title |
Absence of a strong, deep-reaching Antarctic Circumpolar Current zonal flow across the Tasmanian gateway during the Oligocene to early Miocene |
title_short |
Absence of a strong, deep-reaching Antarctic Circumpolar Current zonal flow across the Tasmanian gateway during the Oligocene to early Miocene |
title_full |
Absence of a strong, deep-reaching Antarctic Circumpolar Current zonal flow across the Tasmanian gateway during the Oligocene to early Miocene |
title_fullStr |
Absence of a strong, deep-reaching Antarctic Circumpolar Current zonal flow across the Tasmanian gateway during the Oligocene to early Miocene |
title_full_unstemmed |
Absence of a strong, deep-reaching Antarctic Circumpolar Current zonal flow across the Tasmanian gateway during the Oligocene to early Miocene |
title_sort |
absence of a strong, deep-reaching antarctic circumpolar current zonal flow across the tasmanian gateway during the oligocene to early miocene |
publisher |
Elsevier |
publishDate |
2021 |
url |
http://hdl.handle.net/10044/1/95072 https://doi.org/10.1016/j.gloplacha.2021.103718 |
long_lat |
ENVELOPE(162.500,162.500,-54.000,-54.000) ENVELOPE(120.000,120.000,-69.000,-69.000) |
geographic |
Antarctic Emerald Basin Indian Pacific Ross Sea Southern Ocean The Antarctic Wilkes Land |
geographic_facet |
Antarctic Emerald Basin Indian Pacific Ross Sea Southern Ocean The Antarctic Wilkes Land |
genre |
Antarc* Antarctic Ice Sheet Ross Sea Southern Ocean Wilkes Land |
genre_facet |
Antarc* Antarctic Ice Sheet Ross Sea Southern Ocean Wilkes Land |
op_source |
12 1 |
op_relation |
Global and Planetary Change 0921-8181 http://hdl.handle.net/10044/1/95072 doi:10.1016/j.gloplacha.2021.103718 |
op_rights |
© 2021 Elsevier Ltd. All rights reserved. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Licence http://creativecommons.org/licenses/by-nc-nd/4.0/ http://creativecommons.org/licenses/by-nc-nd/4.0/ |
op_rightsnorm |
CC-BY-NC-ND |
op_doi |
https://doi.org/10.1016/j.gloplacha.2021.103718 |
container_title |
Global and Planetary Change |
container_volume |
208 |
container_start_page |
103718 |
_version_ |
1766247884887425024 |