Antarctic climate, Southern Ocean circulation patterns, and deep-water formation during the Eocene
We assess early-to-middle Eocene seawater neodymium (Nd) isotope records from seven Southern Ocean deep-sea drill sites to evaluate the role of Southern Ocean circulation in long-term Cenozoic climate change. Our study sites are strategically located on either side of the Tasman Gateway and are posi...
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American Geophysical Union (AGU)
2017
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Online Access: | http://hdl.handle.net/10044/1/48866 https://doi.org/10.1002/2017PA003135 |
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ftimperialcol:oai:spiral.imperial.ac.uk:10044/1/48866 2023-05-15T13:51:33+02:00 Antarctic climate, Southern Ocean circulation patterns, and deep-water formation during the Eocene Huck, CE Van de Flierdt, T Bohaty, SM Hammond, SJ Natural Environment Research Council (NERC) Natural Environment Research Council (NERC) Natural Environment Research Council (NERC) 2017-05-31 http://hdl.handle.net/10044/1/48866 https://doi.org/10.1002/2017PA003135 unknown American Geophysical Union (AGU) Paleoceanography © 2017. American Geophysical Union. All Rights Reserved. 0402 Geochemistry 0405 Oceanography 0602 Ecology Journal Article 2017 ftimperialcol https://doi.org/10.1002/2017PA003135 2018-09-16T05:59:08Z We assess early-to-middle Eocene seawater neodymium (Nd) isotope records from seven Southern Ocean deep-sea drill sites to evaluate the role of Southern Ocean circulation in long-term Cenozoic climate change. Our study sites are strategically located on either side of the Tasman Gateway and are positioned at a range of shallow (<500 m) to intermediate/deep (~1000–2500 m) paleowater depths. Unradiogenic seawater Nd isotopic compositions, reconstructed from fish teeth at intermediate/deep Indian Ocean pelagic sites (Ocean Drilling Program (ODP) Sites 738 and 757 and Deep Sea Drilling Project (DSDP) Site 264), indicate a dominant Southern Ocean-sourced contribution to regional deep waters (εNd(t) = −9.3 ± 1.5). IODP Site U1356 off the coast of Adélie Land, a locus of modern-day Antarctic Bottom Water production, is identified as a site of persistent deep water formation from the early Eocene to the Oligocene. East of the Tasman Gateway an additional local source of intermediate/deep water formation is inferred at ODP Site 277 in the SW Pacific Ocean (εNd(t) = −8.7 ± 1.5). Antarctic-proximal shelf sites (ODP Site 1171 and Site U1356) reveal a pronounced erosional event between 49 and 48 Ma, manifested by ~2 εNd unit negative excursions in seawater chemistry toward the composition of bulk sediments at these sites. This erosional event coincides with the termination of peak global warmth following the Early Eocene Climatic Optimum and is associated with documented cooling across the study region and increased export of Antarctic deep waters, highlighting the complexity and importance of Southern Ocean circulation in the greenhouse climate of the Eocene. Article in Journal/Newspaper Antarc* Antarctic Southern Ocean Imperial College London: Spiral Antarctic Indian Pacific Southern Ocean Paleoceanography 32 7 674 691 |
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Imperial College London: Spiral |
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topic |
0402 Geochemistry 0405 Oceanography 0602 Ecology |
spellingShingle |
0402 Geochemistry 0405 Oceanography 0602 Ecology Huck, CE Van de Flierdt, T Bohaty, SM Hammond, SJ Antarctic climate, Southern Ocean circulation patterns, and deep-water formation during the Eocene |
topic_facet |
0402 Geochemistry 0405 Oceanography 0602 Ecology |
description |
We assess early-to-middle Eocene seawater neodymium (Nd) isotope records from seven Southern Ocean deep-sea drill sites to evaluate the role of Southern Ocean circulation in long-term Cenozoic climate change. Our study sites are strategically located on either side of the Tasman Gateway and are positioned at a range of shallow (<500 m) to intermediate/deep (~1000–2500 m) paleowater depths. Unradiogenic seawater Nd isotopic compositions, reconstructed from fish teeth at intermediate/deep Indian Ocean pelagic sites (Ocean Drilling Program (ODP) Sites 738 and 757 and Deep Sea Drilling Project (DSDP) Site 264), indicate a dominant Southern Ocean-sourced contribution to regional deep waters (εNd(t) = −9.3 ± 1.5). IODP Site U1356 off the coast of Adélie Land, a locus of modern-day Antarctic Bottom Water production, is identified as a site of persistent deep water formation from the early Eocene to the Oligocene. East of the Tasman Gateway an additional local source of intermediate/deep water formation is inferred at ODP Site 277 in the SW Pacific Ocean (εNd(t) = −8.7 ± 1.5). Antarctic-proximal shelf sites (ODP Site 1171 and Site U1356) reveal a pronounced erosional event between 49 and 48 Ma, manifested by ~2 εNd unit negative excursions in seawater chemistry toward the composition of bulk sediments at these sites. This erosional event coincides with the termination of peak global warmth following the Early Eocene Climatic Optimum and is associated with documented cooling across the study region and increased export of Antarctic deep waters, highlighting the complexity and importance of Southern Ocean circulation in the greenhouse climate of the Eocene. |
author2 |
Natural Environment Research Council (NERC) Natural Environment Research Council (NERC) Natural Environment Research Council (NERC) |
format |
Article in Journal/Newspaper |
author |
Huck, CE Van de Flierdt, T Bohaty, SM Hammond, SJ |
author_facet |
Huck, CE Van de Flierdt, T Bohaty, SM Hammond, SJ |
author_sort |
Huck, CE |
title |
Antarctic climate, Southern Ocean circulation patterns, and deep-water formation during the Eocene |
title_short |
Antarctic climate, Southern Ocean circulation patterns, and deep-water formation during the Eocene |
title_full |
Antarctic climate, Southern Ocean circulation patterns, and deep-water formation during the Eocene |
title_fullStr |
Antarctic climate, Southern Ocean circulation patterns, and deep-water formation during the Eocene |
title_full_unstemmed |
Antarctic climate, Southern Ocean circulation patterns, and deep-water formation during the Eocene |
title_sort |
antarctic climate, southern ocean circulation patterns, and deep-water formation during the eocene |
publisher |
American Geophysical Union (AGU) |
publishDate |
2017 |
url |
http://hdl.handle.net/10044/1/48866 https://doi.org/10.1002/2017PA003135 |
geographic |
Antarctic Indian Pacific Southern Ocean |
geographic_facet |
Antarctic Indian Pacific Southern Ocean |
genre |
Antarc* Antarctic Southern Ocean |
genre_facet |
Antarc* Antarctic Southern Ocean |
op_relation |
Paleoceanography |
op_rights |
© 2017. American Geophysical Union. All Rights Reserved. |
op_doi |
https://doi.org/10.1002/2017PA003135 |
container_title |
Paleoceanography |
container_volume |
32 |
container_issue |
7 |
container_start_page |
674 |
op_container_end_page |
691 |
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1766255464365948928 |