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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fttriple:oai:gotriple.eu:oai:doaj.org/article:e8789c21bd874714a834ef82c3692e66 2023-05-15T13:55:12+02:00 Contribution of changes in opal productivity and nutrient distribution in the coastal upwelling systems to Late Pliocene/Early Pleistocene climate cooling J. Etourneau C. Ehlert M. Frank P. Martinez R. Schneider 2012-09-01 https://doi.org/10.5194/cp-8-1435-2012 http://www.clim-past.net/8/1435/2012/cp-8-1435-2012.pdf https://doaj.org/article/e8789c21bd874714a834ef82c3692e66 en eng Copernicus Publications doi:10.5194/cp-8-1435-2012 1814-9324 1814-9332 http://www.clim-past.net/8/1435/2012/cp-8-1435-2012.pdf https://doaj.org/article/e8789c21bd874714a834ef82c3692e66 undefined Climate of the Past, Vol 8, Iss 5, Pp 1435-1445 (2012) envir geo Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2012 fttriple https://doi.org/10.5194/cp-8-1435-2012 2023-01-22T17:33:00Z 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 Unknown Antarctic Pacific Southern Ocean Climate of the Past 8 5 1435 1445 |
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English |
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envir geo J. Etourneau C. Ehlert M. Frank P. Martinez R. Schneider Contribution of changes in opal productivity and nutrient distribution in the coastal upwelling systems to Late Pliocene/Early Pleistocene climate cooling |
topic_facet |
envir geo |
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 |
J. Etourneau C. Ehlert M. Frank P. Martinez R. Schneider |
author_facet |
J. Etourneau C. Ehlert M. Frank P. Martinez R. Schneider |
author_sort |
J. Etourneau |
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 |
publishDate |
2012 |
url |
https://doi.org/10.5194/cp-8-1435-2012 http://www.clim-past.net/8/1435/2012/cp-8-1435-2012.pdf https://doaj.org/article/e8789c21bd874714a834ef82c3692e66 |
geographic |
Antarctic Pacific Southern Ocean |
geographic_facet |
Antarctic Pacific Southern Ocean |
genre |
Antarc* Antarctic Southern Ocean |
genre_facet |
Antarc* Antarctic Southern Ocean |
op_source |
Climate of the Past, Vol 8, Iss 5, Pp 1435-1445 (2012) |
op_relation |
doi:10.5194/cp-8-1435-2012 1814-9324 1814-9332 http://www.clim-past.net/8/1435/2012/cp-8-1435-2012.pdf https://doaj.org/article/e8789c21bd874714a834ef82c3692e66 |
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undefined |
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https://doi.org/10.5194/cp-8-1435-2012 |
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Climate of the Past |
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8 |
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1435 |
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1445 |
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