Climate dynamics in the Western equatorial Pacific ocean durig the late Pleistocene
M. Edouard BARD, Professeur, Collège de France - Co-directeur M. Luc BEAUFORT, Chargé de Recherche CNRS, Aix-en-Provence - Directeur de thèse Mme. Elsa CORTIJO, Chargée de Recherche CNRS, Gif-sur-Yvette - Examinateur M. Patrick DE DECKKER, Professeur, Australian National University - Rapporteur M. D...
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2002
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Online Access: | https://theses.hal.science/tel-00008934 https://theses.hal.science/tel-00008934/document https://theses.hal.science/tel-00008934/file/tel-00008934.pdf |
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ftunivnantes:oai:HAL:tel-00008934v1 2023-05-15T18:00:48+02:00 Climate dynamics in the Western equatorial Pacific ocean durig the late Pleistocene Dynamique climatique de l'océan Pacifique ouest équatorial au cours du Pléistocène récent de Garidel-Thoron, Thibault Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE) Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) Université de droit, d'économie et des sciences - Aix-Marseille III Beaufort Luc 2002-07-19 https://theses.hal.science/tel-00008934 https://theses.hal.science/tel-00008934/document https://theses.hal.science/tel-00008934/file/tel-00008934.pdf fr fre HAL CCSD tel-00008934 https://theses.hal.science/tel-00008934 https://theses.hal.science/tel-00008934/document https://theses.hal.science/tel-00008934/file/tel-00008934.pdf info:eu-repo/semantics/OpenAccess https://theses.hal.science/tel-00008934 Géologie appliquée. Université de droit, d'économie et des sciences - Aix-Marseille III, 2002. Français. ⟨NNT : ⟩ Paléoclimat océan Pacifique microfossiles températures de surface production primaire mousson ENSO Pléistocène [SDU.STU.AG]Sciences of the Universe [physics]/Earth Sciences/Applied geology [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology info:eu-repo/semantics/doctoralThesis Theses 2002 ftunivnantes 2023-02-08T00:58:50Z M. Edouard BARD, Professeur, Collège de France - Co-directeur M. Luc BEAUFORT, Chargé de Recherche CNRS, Aix-en-Provence - Directeur de thèse Mme. Elsa CORTIJO, Chargée de Recherche CNRS, Gif-sur-Yvette - Examinateur M. Patrick DE DECKKER, Professeur, Australian National University - Rapporteur M. Dick KROON, Professeur, Vrije Universteit Amsterdam - Rapporteur M. Nicolas THOUVENY, Professeur, Université de la Méditerranée -Examinateur The western equatorial Pacific warm pool (WPWP), warmest ocean area of the globe, fuels the meridian monsoon and zonal Walker atmospheric circulation cells. Using planktonic foraminifera assemblages, stable isotope geochemistry and morphometry, and coccolithophorids assemblages, we investigated past climate dynamics of this area during the Late Pleistocene. We developped a new planktonic foraminifera transfer function which is not biased by the ecosystem structure like was the CLIMAP study. Using this method, the last 185 kyrs SSTs in the WPWP oscillated between 27 and 29.5°C, in agreement with alkenones estimates. The “deep” atmospheric convection over the WPWP was thus a stable feature of the Late Pleistocene climate. These temperatures appear to be modulated by the precession cycles which also force a rocking of the Indo-Pacific thermocline, following an “El Niño-Southern Oscillation-like” mechanism. At millenial time-scale, the high-latitudes Dansgaard-Oeschger cycles were find in past changes in East Asian winter monsoon strength from the northern edge of the WPWP. A 1500 yrs cycle imprints this monsoon record, which is not ice volume modulated, and thus not driven by some high-latitude process. A potential climatic feedback is attributed to thermal dissociation of methane gas-hydrates from low-latitude sedimentary margins. Indeed, a high-resolution of carbon isotopic changes in the WPWP, exhibits the occurrence of large methane gas-hydrates releases during the last glacial stage. L'océan Pacifique ouest équatorial, zone océanique la plus chaude du globe, est au cœur des ... Doctoral or Postdoctoral Thesis Planktonic foraminifera Université de Nantes: HAL-UNIV-NANTES Pacific |
institution |
Open Polar |
collection |
Université de Nantes: HAL-UNIV-NANTES |
op_collection_id |
ftunivnantes |
language |
French |
topic |
Paléoclimat océan Pacifique microfossiles températures de surface production primaire mousson ENSO Pléistocène [SDU.STU.AG]Sciences of the Universe [physics]/Earth Sciences/Applied geology [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology |
spellingShingle |
Paléoclimat océan Pacifique microfossiles températures de surface production primaire mousson ENSO Pléistocène [SDU.STU.AG]Sciences of the Universe [physics]/Earth Sciences/Applied geology [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology de Garidel-Thoron, Thibault Climate dynamics in the Western equatorial Pacific ocean durig the late Pleistocene |
topic_facet |
Paléoclimat océan Pacifique microfossiles températures de surface production primaire mousson ENSO Pléistocène [SDU.STU.AG]Sciences of the Universe [physics]/Earth Sciences/Applied geology [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology |
description |
M. Edouard BARD, Professeur, Collège de France - Co-directeur M. Luc BEAUFORT, Chargé de Recherche CNRS, Aix-en-Provence - Directeur de thèse Mme. Elsa CORTIJO, Chargée de Recherche CNRS, Gif-sur-Yvette - Examinateur M. Patrick DE DECKKER, Professeur, Australian National University - Rapporteur M. Dick KROON, Professeur, Vrije Universteit Amsterdam - Rapporteur M. Nicolas THOUVENY, Professeur, Université de la Méditerranée -Examinateur The western equatorial Pacific warm pool (WPWP), warmest ocean area of the globe, fuels the meridian monsoon and zonal Walker atmospheric circulation cells. Using planktonic foraminifera assemblages, stable isotope geochemistry and morphometry, and coccolithophorids assemblages, we investigated past climate dynamics of this area during the Late Pleistocene. We developped a new planktonic foraminifera transfer function which is not biased by the ecosystem structure like was the CLIMAP study. Using this method, the last 185 kyrs SSTs in the WPWP oscillated between 27 and 29.5°C, in agreement with alkenones estimates. The “deep” atmospheric convection over the WPWP was thus a stable feature of the Late Pleistocene climate. These temperatures appear to be modulated by the precession cycles which also force a rocking of the Indo-Pacific thermocline, following an “El Niño-Southern Oscillation-like” mechanism. At millenial time-scale, the high-latitudes Dansgaard-Oeschger cycles were find in past changes in East Asian winter monsoon strength from the northern edge of the WPWP. A 1500 yrs cycle imprints this monsoon record, which is not ice volume modulated, and thus not driven by some high-latitude process. A potential climatic feedback is attributed to thermal dissociation of methane gas-hydrates from low-latitude sedimentary margins. Indeed, a high-resolution of carbon isotopic changes in the WPWP, exhibits the occurrence of large methane gas-hydrates releases during the last glacial stage. L'océan Pacifique ouest équatorial, zone océanique la plus chaude du globe, est au cœur des ... |
author2 |
Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE) Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) Université de droit, d'économie et des sciences - Aix-Marseille III Beaufort Luc |
format |
Doctoral or Postdoctoral Thesis |
author |
de Garidel-Thoron, Thibault |
author_facet |
de Garidel-Thoron, Thibault |
author_sort |
de Garidel-Thoron, Thibault |
title |
Climate dynamics in the Western equatorial Pacific ocean durig the late Pleistocene |
title_short |
Climate dynamics in the Western equatorial Pacific ocean durig the late Pleistocene |
title_full |
Climate dynamics in the Western equatorial Pacific ocean durig the late Pleistocene |
title_fullStr |
Climate dynamics in the Western equatorial Pacific ocean durig the late Pleistocene |
title_full_unstemmed |
Climate dynamics in the Western equatorial Pacific ocean durig the late Pleistocene |
title_sort |
climate dynamics in the western equatorial pacific ocean durig the late pleistocene |
publisher |
HAL CCSD |
publishDate |
2002 |
url |
https://theses.hal.science/tel-00008934 https://theses.hal.science/tel-00008934/document https://theses.hal.science/tel-00008934/file/tel-00008934.pdf |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
Planktonic foraminifera |
genre_facet |
Planktonic foraminifera |
op_source |
https://theses.hal.science/tel-00008934 Géologie appliquée. Université de droit, d'économie et des sciences - Aix-Marseille III, 2002. Français. ⟨NNT : ⟩ |
op_relation |
tel-00008934 https://theses.hal.science/tel-00008934 https://theses.hal.science/tel-00008934/document https://theses.hal.science/tel-00008934/file/tel-00008934.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1766170057987063808 |