Eocene cooling linked to early flow across the Tasmanian Gateway
The warmest global temperatures of the past 85 million years occurred during a prolonged greenhouse episode known as the Early Eocene Climatic Optimum (52–50 Ma). The Early Eocene Climatic Optimum terminated with a long-term cooling trend that culminated in continental-scale glaciation of Antarctica...
Published in: | Proceedings of the National Academy of Sciences |
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Online Access: | http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3683727 http://www.ncbi.nlm.nih.gov/pubmed/23720311 https://doi.org/10.1073/pnas.1220872110 |
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ftpubmed:oai:pubmedcentral.nih.gov:3683727 2023-05-15T13:49:46+02:00 Eocene cooling linked to early flow across the Tasmanian Gateway Bijl, Peter K. Bendle, James A. P. Bohaty, Steven M. Pross, Jörg Schouten, Stefan Tauxe, Lisa Stickley, Catherine E. McKay, Robert M. Röhl, Ursula Olney, Matthew Sluijs, Appy Escutia, Carlota Brinkhuis, Henk Klaus, Adam Fehr, Annick Williams, Trevor Carr, Stephanie A. Dunbar, Robert B. Gonzàlez, Jhon J. Hayden, Travis G. Iwai, Masao Jimenez-Espejo, Francisco J. Katsuki, Kota Kong, Gee Soo Nakai, Mutsumi Passchier, Sandra Pekar, Stephen F. Riesselman, Christina Sakai, Toyosaburo Shrivastava, Prakash K. Sugisaki, Saiko Tuo, Shouting van de Flierdt, Tina Welsh, Kevin Yamane, Masako 2013-06-11 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3683727 http://www.ncbi.nlm.nih.gov/pubmed/23720311 https://doi.org/10.1073/pnas.1220872110 en eng National Academy of Sciences http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3683727 http://www.ncbi.nlm.nih.gov/pubmed/23720311 http://dx.doi.org/10.1073/pnas.1220872110 Physical Sciences Text 2013 ftpubmed https://doi.org/10.1073/pnas.1220872110 2013-12-15T01:25:55Z The warmest global temperatures of the past 85 million years occurred during a prolonged greenhouse episode known as the Early Eocene Climatic Optimum (52–50 Ma). The Early Eocene Climatic Optimum terminated with a long-term cooling trend that culminated in continental-scale glaciation of Antarctica from 34 Ma onward. Whereas early studies attributed the Eocene transition from greenhouse to icehouse climates to the tectonic opening of Southern Ocean gateways, more recent investigations invoked a dominant role of declining atmospheric greenhouse gas concentrations (e.g., CO2). However, the scarcity of field data has prevented empirical evaluation of these hypotheses. We present marine microfossil and organic geochemical records spanning the early-to-middle Eocene transition from the Wilkes Land Margin, East Antarctica. Dinoflagellate biogeography and sea surface temperature paleothermometry reveal that the earliest throughflow of a westbound Antarctic Counter Current began ∼49–50 Ma through a southern opening of the Tasmanian Gateway. This early opening occurs in conjunction with the simultaneous onset of regional surface water and continental cooling (2–4 °C), evidenced by biomarker- and pollen-based paleothermometry. We interpret that the westbound flowing current flow across the Tasmanian Gateway resulted in cooling of Antarctic surface waters and coasts, which was conveyed to global intermediate waters through invigorated deep convection in southern high latitudes. Although atmospheric CO2 forcing alone would provide a more uniform middle Eocene cooling, the opening of the Tasmanian Gateway better explains Southern Ocean surface water and global deep ocean cooling in the apparent absence of (sub-) equatorial cooling. Text Antarc* Antarctic Antarctica East Antarctica Southern Ocean Wilkes Land PubMed Central (PMC) Antarctic East Antarctica Southern Ocean Wilkes Land ENVELOPE(120.000,120.000,-69.000,-69.000) Proceedings of the National Academy of Sciences 110 24 9645 9650 |
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Open Polar |
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PubMed Central (PMC) |
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ftpubmed |
language |
English |
topic |
Physical Sciences |
spellingShingle |
Physical Sciences Bijl, Peter K. Bendle, James A. P. Bohaty, Steven M. Pross, Jörg Schouten, Stefan Tauxe, Lisa Stickley, Catherine E. McKay, Robert M. Röhl, Ursula Olney, Matthew Sluijs, Appy Escutia, Carlota Brinkhuis, Henk Klaus, Adam Fehr, Annick Williams, Trevor Carr, Stephanie A. Dunbar, Robert B. Gonzàlez, Jhon J. Hayden, Travis G. Iwai, Masao Jimenez-Espejo, Francisco J. Katsuki, Kota Kong, Gee Soo Nakai, Mutsumi Passchier, Sandra Pekar, Stephen F. Riesselman, Christina Sakai, Toyosaburo Shrivastava, Prakash K. Sugisaki, Saiko Tuo, Shouting van de Flierdt, Tina Welsh, Kevin Yamane, Masako Eocene cooling linked to early flow across the Tasmanian Gateway |
topic_facet |
Physical Sciences |
description |
The warmest global temperatures of the past 85 million years occurred during a prolonged greenhouse episode known as the Early Eocene Climatic Optimum (52–50 Ma). The Early Eocene Climatic Optimum terminated with a long-term cooling trend that culminated in continental-scale glaciation of Antarctica from 34 Ma onward. Whereas early studies attributed the Eocene transition from greenhouse to icehouse climates to the tectonic opening of Southern Ocean gateways, more recent investigations invoked a dominant role of declining atmospheric greenhouse gas concentrations (e.g., CO2). However, the scarcity of field data has prevented empirical evaluation of these hypotheses. We present marine microfossil and organic geochemical records spanning the early-to-middle Eocene transition from the Wilkes Land Margin, East Antarctica. Dinoflagellate biogeography and sea surface temperature paleothermometry reveal that the earliest throughflow of a westbound Antarctic Counter Current began ∼49–50 Ma through a southern opening of the Tasmanian Gateway. This early opening occurs in conjunction with the simultaneous onset of regional surface water and continental cooling (2–4 °C), evidenced by biomarker- and pollen-based paleothermometry. We interpret that the westbound flowing current flow across the Tasmanian Gateway resulted in cooling of Antarctic surface waters and coasts, which was conveyed to global intermediate waters through invigorated deep convection in southern high latitudes. Although atmospheric CO2 forcing alone would provide a more uniform middle Eocene cooling, the opening of the Tasmanian Gateway better explains Southern Ocean surface water and global deep ocean cooling in the apparent absence of (sub-) equatorial cooling. |
format |
Text |
author |
Bijl, Peter K. Bendle, James A. P. Bohaty, Steven M. Pross, Jörg Schouten, Stefan Tauxe, Lisa Stickley, Catherine E. McKay, Robert M. Röhl, Ursula Olney, Matthew Sluijs, Appy Escutia, Carlota Brinkhuis, Henk Klaus, Adam Fehr, Annick Williams, Trevor Carr, Stephanie A. Dunbar, Robert B. Gonzàlez, Jhon J. Hayden, Travis G. Iwai, Masao Jimenez-Espejo, Francisco J. Katsuki, Kota Kong, Gee Soo Nakai, Mutsumi Passchier, Sandra Pekar, Stephen F. Riesselman, Christina Sakai, Toyosaburo Shrivastava, Prakash K. Sugisaki, Saiko Tuo, Shouting van de Flierdt, Tina Welsh, Kevin Yamane, Masako |
author_facet |
Bijl, Peter K. Bendle, James A. P. Bohaty, Steven M. Pross, Jörg Schouten, Stefan Tauxe, Lisa Stickley, Catherine E. McKay, Robert M. Röhl, Ursula Olney, Matthew Sluijs, Appy Escutia, Carlota Brinkhuis, Henk Klaus, Adam Fehr, Annick Williams, Trevor Carr, Stephanie A. Dunbar, Robert B. Gonzàlez, Jhon J. Hayden, Travis G. Iwai, Masao Jimenez-Espejo, Francisco J. Katsuki, Kota Kong, Gee Soo Nakai, Mutsumi Passchier, Sandra Pekar, Stephen F. Riesselman, Christina Sakai, Toyosaburo Shrivastava, Prakash K. Sugisaki, Saiko Tuo, Shouting van de Flierdt, Tina Welsh, Kevin Yamane, Masako |
author_sort |
Bijl, Peter K. |
title |
Eocene cooling linked to early flow across the Tasmanian Gateway |
title_short |
Eocene cooling linked to early flow across the Tasmanian Gateway |
title_full |
Eocene cooling linked to early flow across the Tasmanian Gateway |
title_fullStr |
Eocene cooling linked to early flow across the Tasmanian Gateway |
title_full_unstemmed |
Eocene cooling linked to early flow across the Tasmanian Gateway |
title_sort |
eocene cooling linked to early flow across the tasmanian gateway |
publisher |
National Academy of Sciences |
publishDate |
2013 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3683727 http://www.ncbi.nlm.nih.gov/pubmed/23720311 https://doi.org/10.1073/pnas.1220872110 |
long_lat |
ENVELOPE(120.000,120.000,-69.000,-69.000) |
geographic |
Antarctic East Antarctica Southern Ocean Wilkes Land |
geographic_facet |
Antarctic East Antarctica Southern Ocean Wilkes Land |
genre |
Antarc* Antarctic Antarctica East Antarctica Southern Ocean Wilkes Land |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica Southern Ocean Wilkes Land |
op_relation |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3683727 http://www.ncbi.nlm.nih.gov/pubmed/23720311 http://dx.doi.org/10.1073/pnas.1220872110 |
op_doi |
https://doi.org/10.1073/pnas.1220872110 |
container_title |
Proceedings of the National Academy of Sciences |
container_volume |
110 |
container_issue |
24 |
container_start_page |
9645 |
op_container_end_page |
9650 |
_version_ |
1766252225449951232 |