Pliocene climate change of the Southwest Pacific and the impact of ocean gateways
The transition from the early Pliocene “Warmhouse” towards the present “Icehouse” climate and the role of Gateway dynamics are intensively debated. Both, the constrictions of the Central American Seaway and the Indonesian Gateway affected ocean circulation and climate during the Pliocene epoch. Here...
Published in: | Earth and Planetary Science Letters |
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ftoceanrep:oai:oceanrep.geomar.de:10275 2023-05-15T13:55:15+02:00 Pliocene climate change of the Southwest Pacific and the impact of ocean gateways Karas, Cyrus Nürnberg, Dirk Tiedemann, Ralf Garbe-Schönberg, Dieter 2011 text https://oceanrep.geomar.de/id/eprint/10275/ https://oceanrep.geomar.de/id/eprint/10275/2/Karas_et_al_%28in_press%29-1.pdf https://doi.org/10.1016/j.epsl.2010.10.028 en eng Elsevier https://oceanrep.geomar.de/id/eprint/10275/2/Karas_et_al_%28in_press%29-1.pdf Karas, C., Nürnberg, D. , Tiedemann, R. and Garbe-Schönberg, D. (2011) Pliocene climate change of the Southwest Pacific and the impact of ocean gateways. Earth and Planetary Science Letters, 301 (1-2). pp. 117-124. DOI 10.1016/j.epsl.2010.10.028 <https://doi.org/10.1016/j.epsl.2010.10.028>. doi:10.1016/j.epsl.2010.10.028 info:eu-repo/semantics/restrictedAccess Article PeerReviewed 2011 ftoceanrep https://doi.org/10.1016/j.epsl.2010.10.028 2023-04-07T14:58:19Z The transition from the early Pliocene “Warmhouse” towards the present “Icehouse” climate and the role of Gateway dynamics are intensively debated. Both, the constrictions of the Central American Seaway and the Indonesian Gateway affected ocean circulation and climate during the Pliocene epoch. Here, we use combined δ18O and Mg/Ca ratios of planktonic foraminifera (marine protozoa) from surface and subsurface levels to reconstruct the thermal structure and changes in salinities from the Southwest Pacific Deep Sea Drilling Project (DSDP) Site 590B from 6.5 to 2.5 Ma. Our data suggest a gradual cooling of ~ 2 °C and freshening of the sea surface during ~ 4.6–4 Ma with an increased meridional temperature gradient between the West Pacific Warm Pool and the Southwest Pacific when the closing of the Central American Seaway reached a critical threshold. After ~ 3.5 Ma, the restricted Indonesian Gateway might have amplified the East Australian Current, allowing enhanced heat transport towards the Southwest Pacific with reduced meridional temperature gradients when the global climate gradually cooled. At the same time our data suggest a cooling and freshening of Subantarctic Mode Water (SAMW) or/and an increased northward flow of SAMW towards Site 590B, possibly a first step towards the present Antarctic Frontal System. Article in Journal/Newspaper Antarc* Antarctic Planktonic foraminifera OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Antarctic Pacific Earth and Planetary Science Letters 301 1-2 117 124 |
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Open Polar |
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OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
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ftoceanrep |
language |
English |
description |
The transition from the early Pliocene “Warmhouse” towards the present “Icehouse” climate and the role of Gateway dynamics are intensively debated. Both, the constrictions of the Central American Seaway and the Indonesian Gateway affected ocean circulation and climate during the Pliocene epoch. Here, we use combined δ18O and Mg/Ca ratios of planktonic foraminifera (marine protozoa) from surface and subsurface levels to reconstruct the thermal structure and changes in salinities from the Southwest Pacific Deep Sea Drilling Project (DSDP) Site 590B from 6.5 to 2.5 Ma. Our data suggest a gradual cooling of ~ 2 °C and freshening of the sea surface during ~ 4.6–4 Ma with an increased meridional temperature gradient between the West Pacific Warm Pool and the Southwest Pacific when the closing of the Central American Seaway reached a critical threshold. After ~ 3.5 Ma, the restricted Indonesian Gateway might have amplified the East Australian Current, allowing enhanced heat transport towards the Southwest Pacific with reduced meridional temperature gradients when the global climate gradually cooled. At the same time our data suggest a cooling and freshening of Subantarctic Mode Water (SAMW) or/and an increased northward flow of SAMW towards Site 590B, possibly a first step towards the present Antarctic Frontal System. |
format |
Article in Journal/Newspaper |
author |
Karas, Cyrus Nürnberg, Dirk Tiedemann, Ralf Garbe-Schönberg, Dieter |
spellingShingle |
Karas, Cyrus Nürnberg, Dirk Tiedemann, Ralf Garbe-Schönberg, Dieter Pliocene climate change of the Southwest Pacific and the impact of ocean gateways |
author_facet |
Karas, Cyrus Nürnberg, Dirk Tiedemann, Ralf Garbe-Schönberg, Dieter |
author_sort |
Karas, Cyrus |
title |
Pliocene climate change of the Southwest Pacific and the impact of ocean gateways |
title_short |
Pliocene climate change of the Southwest Pacific and the impact of ocean gateways |
title_full |
Pliocene climate change of the Southwest Pacific and the impact of ocean gateways |
title_fullStr |
Pliocene climate change of the Southwest Pacific and the impact of ocean gateways |
title_full_unstemmed |
Pliocene climate change of the Southwest Pacific and the impact of ocean gateways |
title_sort |
pliocene climate change of the southwest pacific and the impact of ocean gateways |
publisher |
Elsevier |
publishDate |
2011 |
url |
https://oceanrep.geomar.de/id/eprint/10275/ https://oceanrep.geomar.de/id/eprint/10275/2/Karas_et_al_%28in_press%29-1.pdf https://doi.org/10.1016/j.epsl.2010.10.028 |
geographic |
Antarctic Pacific |
geographic_facet |
Antarctic Pacific |
genre |
Antarc* Antarctic Planktonic foraminifera |
genre_facet |
Antarc* Antarctic Planktonic foraminifera |
op_relation |
https://oceanrep.geomar.de/id/eprint/10275/2/Karas_et_al_%28in_press%29-1.pdf Karas, C., Nürnberg, D. , Tiedemann, R. and Garbe-Schönberg, D. (2011) Pliocene climate change of the Southwest Pacific and the impact of ocean gateways. Earth and Planetary Science Letters, 301 (1-2). pp. 117-124. DOI 10.1016/j.epsl.2010.10.028 <https://doi.org/10.1016/j.epsl.2010.10.028>. doi:10.1016/j.epsl.2010.10.028 |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1016/j.epsl.2010.10.028 |
container_title |
Earth and Planetary Science Letters |
container_volume |
301 |
container_issue |
1-2 |
container_start_page |
117 |
op_container_end_page |
124 |
_version_ |
1766261624241389568 |