Late Neogene history of deepwater ventilation in the Southern Ocean
We compiled carbon isotope records from the North Atlantic, South Atlantic, and Pacific oceans to estimate changes in vertical and interbasinal δ13C gradients for the last 9 Myr. Benthic δ13C values of deep water in the South Atlantic decreased in a series of steps at ∼7, 2.75, and 1.55 Ma away from...
Published in: | Geochemistry, Geophysics, Geosystems |
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Online Access: | http://eprints.esc.cam.ac.uk/386/ http://eprints.esc.cam.ac.uk/386/1/Hodell_3G_7_9_2006.pdf https://doi.org/10.1029/2005GC001211 |
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ftucambridgeesc:oai:eprints.esc.cam.ac.uk:386 2023-05-15T13:32:21+02:00 Late Neogene history of deepwater ventilation in the Southern Ocean Hodell, D. A. Venz-Curtis, K. A. 2006-09 application/pdf http://eprints.esc.cam.ac.uk/386/ http://eprints.esc.cam.ac.uk/386/1/Hodell_3G_7_9_2006.pdf https://doi.org/10.1029/2005GC001211 en eng AGU http://eprints.esc.cam.ac.uk/386/1/Hodell_3G_7_9_2006.pdf Hodell, D. A. and Venz-Curtis, K. A. (2006) Late Neogene history of deepwater ventilation in the Southern Ocean. Geochemistry Geophysics Geosystems, 7 (9). Q09001. ISSN 1525-2027 DOI https://doi.org/10.1029/2005GC001211 <https://doi.org/10.1029/2005GC001211> 01 - Climate Change and Earth-Ocean Atmosphere Systems Article PeerReviewed 2006 ftucambridgeesc https://doi.org/10.1029/2005GC001211 2020-08-27T18:08:30Z We compiled carbon isotope records from the North Atlantic, South Atlantic, and Pacific oceans to estimate changes in vertical and interbasinal δ13C gradients for the last 9 Myr. Benthic δ13C values of deep water in the South Atlantic decreased in a series of steps at ∼7, 2.75, and 1.55 Ma away from the North Atlantic and toward the Pacific. The benthic δ13C of intermediate water in the South Atlantic evolved differently from deep waters, resulting in an increase in the intermediate-to-deep δ13C gradient (Δ13CID). The Δ13CID increased in steps at ∼2.75 and 1.55 Ma, marking the development and intensification of a chemical divide in the Atlantic Ocean between well-ventilated intermediate water and poorly ventilated deep water. We suggest these changes in interbasinal and vertical gradients resulted from decreasing Northern Component Water and reduced ventilation of Southern Component Water (SCW). The latter was caused by several interrelated processes in Antarctic sources areas, including increased sea ice cover, enhanced surface water stratification, decreased Ekman-induced upwelling, and reduced vertical mixing across the thermocline. Because Antarctic surface water processes and deepwater ventilation rates ultimately influence atmospheric CO2 concentration, these processes may have acted as a positive feedback that contributed to the major cooling steps in late Neogene climate. Article in Journal/Newspaper Antarc* Antarctic North Atlantic Sea ice Southern Ocean University of Cambridge, Department of Earth Sciences: ESC Publications Antarctic Pacific Southern Ocean Geochemistry, Geophysics, Geosystems 7 9 n/a n/a |
institution |
Open Polar |
collection |
University of Cambridge, Department of Earth Sciences: ESC Publications |
op_collection_id |
ftucambridgeesc |
language |
English |
topic |
01 - Climate Change and Earth-Ocean Atmosphere Systems |
spellingShingle |
01 - Climate Change and Earth-Ocean Atmosphere Systems Hodell, D. A. Venz-Curtis, K. A. Late Neogene history of deepwater ventilation in the Southern Ocean |
topic_facet |
01 - Climate Change and Earth-Ocean Atmosphere Systems |
description |
We compiled carbon isotope records from the North Atlantic, South Atlantic, and Pacific oceans to estimate changes in vertical and interbasinal δ13C gradients for the last 9 Myr. Benthic δ13C values of deep water in the South Atlantic decreased in a series of steps at ∼7, 2.75, and 1.55 Ma away from the North Atlantic and toward the Pacific. The benthic δ13C of intermediate water in the South Atlantic evolved differently from deep waters, resulting in an increase in the intermediate-to-deep δ13C gradient (Δ13CID). The Δ13CID increased in steps at ∼2.75 and 1.55 Ma, marking the development and intensification of a chemical divide in the Atlantic Ocean between well-ventilated intermediate water and poorly ventilated deep water. We suggest these changes in interbasinal and vertical gradients resulted from decreasing Northern Component Water and reduced ventilation of Southern Component Water (SCW). The latter was caused by several interrelated processes in Antarctic sources areas, including increased sea ice cover, enhanced surface water stratification, decreased Ekman-induced upwelling, and reduced vertical mixing across the thermocline. Because Antarctic surface water processes and deepwater ventilation rates ultimately influence atmospheric CO2 concentration, these processes may have acted as a positive feedback that contributed to the major cooling steps in late Neogene climate. |
format |
Article in Journal/Newspaper |
author |
Hodell, D. A. Venz-Curtis, K. A. |
author_facet |
Hodell, D. A. Venz-Curtis, K. A. |
author_sort |
Hodell, D. A. |
title |
Late Neogene history of deepwater ventilation in the Southern Ocean |
title_short |
Late Neogene history of deepwater ventilation in the Southern Ocean |
title_full |
Late Neogene history of deepwater ventilation in the Southern Ocean |
title_fullStr |
Late Neogene history of deepwater ventilation in the Southern Ocean |
title_full_unstemmed |
Late Neogene history of deepwater ventilation in the Southern Ocean |
title_sort |
late neogene history of deepwater ventilation in the southern ocean |
publisher |
AGU |
publishDate |
2006 |
url |
http://eprints.esc.cam.ac.uk/386/ http://eprints.esc.cam.ac.uk/386/1/Hodell_3G_7_9_2006.pdf https://doi.org/10.1029/2005GC001211 |
geographic |
Antarctic Pacific Southern Ocean |
geographic_facet |
Antarctic Pacific Southern Ocean |
genre |
Antarc* Antarctic North Atlantic Sea ice Southern Ocean |
genre_facet |
Antarc* Antarctic North Atlantic Sea ice Southern Ocean |
op_relation |
http://eprints.esc.cam.ac.uk/386/1/Hodell_3G_7_9_2006.pdf Hodell, D. A. and Venz-Curtis, K. A. (2006) Late Neogene history of deepwater ventilation in the Southern Ocean. Geochemistry Geophysics Geosystems, 7 (9). Q09001. ISSN 1525-2027 DOI https://doi.org/10.1029/2005GC001211 <https://doi.org/10.1029/2005GC001211> |
op_doi |
https://doi.org/10.1029/2005GC001211 |
container_title |
Geochemistry, Geophysics, Geosystems |
container_volume |
7 |
container_issue |
9 |
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n/a |
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n/a |
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1766026050788130816 |