Contribution of changes in opal productivity and nutrient distribution in the coastal upwelling systems to Late Pliocene/Early Pleistocene climate cooling
The global Late Pliocene/Early Pleistocene cooling (~3.0–2.0 million years ago – Ma) concurred with extremely high diatom and biogenic opal production in most of the major coastal upwelling regions. This phenomenon was particularly pronounced in the Benguela upwelling system (BUS), off Namibia, wher...
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ftoceanrep:oai:oceanrep.geomar.de:16405 2023-05-15T14:09:40+02:00 Contribution of changes in opal productivity and nutrient distribution in the coastal upwelling systems to Late Pliocene/Early Pleistocene climate cooling Etourneau, Johan Ehlert, Claudia Frank, Martin Martinez, P. Schneider, Ralph 2012 text https://oceanrep.geomar.de/id/eprint/16405/ https://oceanrep.geomar.de/id/eprint/16405/1/Etourneau%20et%20al%202012.pdf https://doi.org/10.5194/cp-8-1435-2012 en eng Copernicus Publications (EGU) https://oceanrep.geomar.de/id/eprint/16405/1/Etourneau%20et%20al%202012.pdf Etourneau, J., Ehlert, C., Frank, M. , Martinez, P. and Schneider, R. (2012) Contribution of changes in opal productivity and nutrient distribution in the coastal upwelling systems to Late Pliocene/Early Pleistocene climate cooling. Open Access Climate of the Past, 8 (5). pp. 1435-1445. DOI 10.5194/cp-8-1435-2012 <https://doi.org/10.5194/cp-8-1435-2012>. doi:10.5194/cp-8-1435-2012 cc_by info:eu-repo/semantics/openAccess Article PeerReviewed 2012 ftoceanrep https://doi.org/10.5194/cp-8-1435-2012 2023-04-07T15:05:35Z The global Late Pliocene/Early Pleistocene cooling (~3.0–2.0 million years ago – Ma) concurred with extremely high diatom and biogenic opal production in most of the major coastal upwelling regions. This phenomenon was particularly pronounced in the Benguela upwelling system (BUS), off Namibia, where it is known as the Matuyama Diatom Maximum (MDM). Our study focuses on a new diatom silicon isotope (δ30Si) record covering the MDM in the BUS. Unexpectedly, the variations in δ30Si signal follow biogenic opal content, whereby the highest δ30Si values correspond to the highest biogenic opal content. We interpret the higher δ30Si values during the MDM as a result of a stronger degree of silicate utilisation in the surface waters caused by high productivity of mat-forming diatom species. This was most likely promoted by weak upwelling intensity dominating the BUS during the Late Pliocene/Early Pleistocene cooling combined with a large silicate supply derived from a strong Southern Ocean nutrient leakage responding to the expansion of Antarctic ice cover and the resulting stratification of the polar ocean 3.0–2.7 Ma ago. A similar scenario is hypothesized for other major coastal upwelling systems (e.g. off California) during this time interval, suggesting that the efficiency of the biological carbon pump was probably sufficiently enhanced in these regions during the MDM to have significantly increased the transport of atmospheric CO2 to the deep ocean. In addition, the coeval extension of the area of surface water stratification in both the Southern Ocean and the North Pacific, which decreased CO2 release to the atmosphere, led to further enhanced atmospheric CO2 drawn-down and thus contributed significantly to Late Pliocene/Early Pleistocene cooling. Article in Journal/Newspaper Antarc* Antarctic Southern Ocean OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Antarctic Pacific Southern Ocean Climate of the Past 8 5 1435 1445 |
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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 global Late Pliocene/Early Pleistocene cooling (~3.0–2.0 million years ago – Ma) concurred with extremely high diatom and biogenic opal production in most of the major coastal upwelling regions. This phenomenon was particularly pronounced in the Benguela upwelling system (BUS), off Namibia, where it is known as the Matuyama Diatom Maximum (MDM). Our study focuses on a new diatom silicon isotope (δ30Si) record covering the MDM in the BUS. Unexpectedly, the variations in δ30Si signal follow biogenic opal content, whereby the highest δ30Si values correspond to the highest biogenic opal content. We interpret the higher δ30Si values during the MDM as a result of a stronger degree of silicate utilisation in the surface waters caused by high productivity of mat-forming diatom species. This was most likely promoted by weak upwelling intensity dominating the BUS during the Late Pliocene/Early Pleistocene cooling combined with a large silicate supply derived from a strong Southern Ocean nutrient leakage responding to the expansion of Antarctic ice cover and the resulting stratification of the polar ocean 3.0–2.7 Ma ago. A similar scenario is hypothesized for other major coastal upwelling systems (e.g. off California) during this time interval, suggesting that the efficiency of the biological carbon pump was probably sufficiently enhanced in these regions during the MDM to have significantly increased the transport of atmospheric CO2 to the deep ocean. In addition, the coeval extension of the area of surface water stratification in both the Southern Ocean and the North Pacific, which decreased CO2 release to the atmosphere, led to further enhanced atmospheric CO2 drawn-down and thus contributed significantly to Late Pliocene/Early Pleistocene cooling. |
format |
Article in Journal/Newspaper |
author |
Etourneau, Johan Ehlert, Claudia Frank, Martin Martinez, P. Schneider, Ralph |
spellingShingle |
Etourneau, Johan Ehlert, Claudia Frank, Martin Martinez, P. Schneider, Ralph Contribution of changes in opal productivity and nutrient distribution in the coastal upwelling systems to Late Pliocene/Early Pleistocene climate cooling |
author_facet |
Etourneau, Johan Ehlert, Claudia Frank, Martin Martinez, P. Schneider, Ralph |
author_sort |
Etourneau, Johan |
title |
Contribution of changes in opal productivity and nutrient distribution in the coastal upwelling systems to Late Pliocene/Early Pleistocene climate cooling |
title_short |
Contribution of changes in opal productivity and nutrient distribution in the coastal upwelling systems to Late Pliocene/Early Pleistocene climate cooling |
title_full |
Contribution of changes in opal productivity and nutrient distribution in the coastal upwelling systems to Late Pliocene/Early Pleistocene climate cooling |
title_fullStr |
Contribution of changes in opal productivity and nutrient distribution in the coastal upwelling systems to Late Pliocene/Early Pleistocene climate cooling |
title_full_unstemmed |
Contribution of changes in opal productivity and nutrient distribution in the coastal upwelling systems to Late Pliocene/Early Pleistocene climate cooling |
title_sort |
contribution of changes in opal productivity and nutrient distribution in the coastal upwelling systems to late pliocene/early pleistocene climate cooling |
publisher |
Copernicus Publications (EGU) |
publishDate |
2012 |
url |
https://oceanrep.geomar.de/id/eprint/16405/ https://oceanrep.geomar.de/id/eprint/16405/1/Etourneau%20et%20al%202012.pdf https://doi.org/10.5194/cp-8-1435-2012 |
geographic |
Antarctic Pacific Southern Ocean |
geographic_facet |
Antarctic Pacific Southern Ocean |
genre |
Antarc* Antarctic Southern Ocean |
genre_facet |
Antarc* Antarctic Southern Ocean |
op_relation |
https://oceanrep.geomar.de/id/eprint/16405/1/Etourneau%20et%20al%202012.pdf Etourneau, J., Ehlert, C., Frank, M. , Martinez, P. and Schneider, R. (2012) Contribution of changes in opal productivity and nutrient distribution in the coastal upwelling systems to Late Pliocene/Early Pleistocene climate cooling. Open Access Climate of the Past, 8 (5). pp. 1435-1445. DOI 10.5194/cp-8-1435-2012 <https://doi.org/10.5194/cp-8-1435-2012>. doi:10.5194/cp-8-1435-2012 |
op_rights |
cc_by info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/cp-8-1435-2012 |
container_title |
Climate of the Past |
container_volume |
8 |
container_issue |
5 |
container_start_page |
1435 |
op_container_end_page |
1445 |
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1766281687829839872 |