Contribution of changes in opal productivity and nutrient distribution in the coastal upwelling systems to Late Pliocene/Early Pleistocene climate cooling
International audience 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 (...
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HAL CCSD
2012
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Online Access: | https://hal.science/hal-04115389 https://doi.org/10.5194/cp-8-1435-201210.5194/cpd-8-669-2012 |
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openpolar |
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Open Polar |
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Institut national des sciences de l'Univers: HAL-INSU |
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English |
topic |
Earth Science [SDU]Sciences of the Universe [physics] |
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Earth Science [SDU]Sciences of the Universe [physics] Etourneau, J. Ehlert, C. Frank, M. Martinez, P. Schneider, R. Contribution of changes in opal productivity and nutrient distribution in the coastal upwelling systems to Late Pliocene/Early Pleistocene climate cooling |
topic_facet |
Earth Science [SDU]Sciences of the Universe [physics] |
description |
International audience 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 (δ 30 Si) record covering the MDM in the BUS. Unexpectedly, the variations in δ 30 Si signal follow biogenic opal content, whereby the highest δ 30 Si values correspond to the highest biogenic opal content. We interpret the higher δ 30 Si 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 CO 2 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 CO 2 release to the atmosphere, led to further enhanced atmospheric CO 2 drawn-down and thus contributed significantly to Late Pliocene/Early Pleistocene cooling. |
author2 |
Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN) Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)) École normale supérieure - Paris (ENS-PSL) Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL) Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Etourneau, J. Ehlert, C. Frank, M. Martinez, P. Schneider, R. |
author_facet |
Etourneau, J. Ehlert, C. Frank, M. Martinez, P. Schneider, R. |
author_sort |
Etourneau, J. |
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 |
HAL CCSD |
publishDate |
2012 |
url |
https://hal.science/hal-04115389 https://doi.org/10.5194/cp-8-1435-201210.5194/cpd-8-669-2012 |
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 https://hal.science/hal-04115389 Climate of the Past, 2012, 8, pp.1435-1445. ⟨10.5194/cp-8-1435-201210.5194/cpd-8-669-2012⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/cp-8-1435-201210.5194/cpd-8-669-2012 hal-04115389 https://hal.science/hal-04115389 BIBCODE: 2012CliPa.8.1435E doi:10.5194/cp-8-1435-201210.5194/cpd-8-669-2012 |
op_doi |
https://doi.org/10.5194/cp-8-1435-201210.5194/cpd-8-669-2012 |
_version_ |
1769009848911921152 |
spelling |
ftinsu:oai:HAL:hal-04115389v1 2023-06-18T03:37:03+02:00 Contribution of changes in opal productivity and nutrient distribution in the coastal upwelling systems to Late Pliocene/Early Pleistocene climate cooling Etourneau, J. Ehlert, C. Frank, M. Martinez, P. Schneider, R. Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN) Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)) École normale supérieure - Paris (ENS-PSL) Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL) Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS) 2012 https://hal.science/hal-04115389 https://doi.org/10.5194/cp-8-1435-201210.5194/cpd-8-669-2012 en eng HAL CCSD info:eu-repo/semantics/altIdentifier/doi/10.5194/cp-8-1435-201210.5194/cpd-8-669-2012 hal-04115389 https://hal.science/hal-04115389 BIBCODE: 2012CliPa.8.1435E doi:10.5194/cp-8-1435-201210.5194/cpd-8-669-2012 Climate of the Past https://hal.science/hal-04115389 Climate of the Past, 2012, 8, pp.1435-1445. ⟨10.5194/cp-8-1435-201210.5194/cpd-8-669-2012⟩ Earth Science [SDU]Sciences of the Universe [physics] info:eu-repo/semantics/article Journal articles 2012 ftinsu https://doi.org/10.5194/cp-8-1435-201210.5194/cpd-8-669-2012 2023-06-05T19:25:47Z International audience 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 (δ 30 Si) record covering the MDM in the BUS. Unexpectedly, the variations in δ 30 Si signal follow biogenic opal content, whereby the highest δ 30 Si values correspond to the highest biogenic opal content. We interpret the higher δ 30 Si 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 CO 2 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 CO 2 release to the atmosphere, led to further enhanced atmospheric CO 2 drawn-down and thus contributed significantly to Late Pliocene/Early Pleistocene cooling. Article in Journal/Newspaper Antarc* Antarctic Southern Ocean Institut national des sciences de l'Univers: HAL-INSU Antarctic Pacific Southern Ocean |