Palaeohydrological changes over the last 50 ky in the central Gulf of Cadiz: complex forcing mechanisms mixing multi-scale processes
International audience New dinoflagellate cyst (dinocyst) analyses were carried out at high resolution in core MD99-2339, retrieved from a contouritic field in the central part of the Gulf of Cadiz, for the Marine Isotope Stage (MIS) 3 interval, allowing for discussion of palaeohydrological changes...
Published in: | Biogeosciences |
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Main Authors: | , , , |
Other Authors: | , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
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HAL CCSD
2016
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Online Access: | https://hal-insu.archives-ouvertes.fr/insu-03678729 https://hal-insu.archives-ouvertes.fr/insu-03678729/document https://hal-insu.archives-ouvertes.fr/insu-03678729/file/bg-13-5357-2016.pdf https://doi.org/10.5194/bg-13-5357-2016 |
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ftunivnantes:oai:HAL:insu-03678729v1 |
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Université de Nantes: HAL-UNIV-NANTES |
op_collection_id |
ftunivnantes |
language |
English |
topic |
[SDU]Sciences of the Universe [physics] |
spellingShingle |
[SDU]Sciences of the Universe [physics] Penaud, Aurélie Eynaud, Frédérique Luise Voelker, Antje Helga Turon, Jean-Louis Palaeohydrological changes over the last 50 ky in the central Gulf of Cadiz: complex forcing mechanisms mixing multi-scale processes |
topic_facet |
[SDU]Sciences of the Universe [physics] |
description |
International audience New dinoflagellate cyst (dinocyst) analyses were carried out at high resolution in core MD99-2339, retrieved from a contouritic field in the central part of the Gulf of Cadiz, for the Marine Isotope Stage (MIS) 3 interval, allowing for discussion of palaeohydrological changes over the last 50 ky in the subtropical NE Atlantic Ocean. Some index dinocyst taxa, according to their (palaeo)ecological significance, shed light on significant sea-surface changes. Superimposed on the general decreasing pattern of dinocyst export to the seafloor over the last 50 ky, paralleling the general context of decreasing aeolian dust fertilization, a complex variability in dinocyst assemblages was detected at the millennial timescale. Enhanced fluvial discharges occurred during Greenland Interstadials (GIs), especially GI 1, 8 and 12, while enhanced upwelling cell dynamics were suggested during the Last Glacial Maximum and Heinrich Stadials. Finally, during the early Holocene, and more specifically during the Sapropel 1 interval (around 7-9 ka BP), we evidenced a strong decrease in dinocyst fluxes, which occurred synchronously to a strong reduction in Mediterranean Outflow Water strength and which we attributed to an advection of warm and nutrient-poor subtropical North Atlantic Central Waters. Over the last 50 ky, our study thus allows for capturing and documenting the fine tuning existing between terrestrial and marine realms in North Atlantic subtropical latitudes, in response to not only the regional climate pattern but also monsoonal forcing interfering during precession-driven Northern Hemisphere insolation maxima. This mechanism, well expressed during the Holocene, is superimposed on the pervasive role of the obliquity as a first major trigger for explaining migration of dinocyst productive centres in the NE Atlantic margin to the subtropical (temperate) latitudes during glacial (interglacial) periods. |
author2 |
Domaines Océaniques (LDO) Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Observatoire des Sciences de l'Univers-Institut d'écologie et environnement-Centre National de la Recherche Scientifique (CNRS) Environnements et Paléoenvironnements OCéaniques (EPOC) Observatoire aquitain des sciences de l'univers (OASU) Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE) Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Penaud, Aurélie Eynaud, Frédérique Luise Voelker, Antje Helga Turon, Jean-Louis |
author_facet |
Penaud, Aurélie Eynaud, Frédérique Luise Voelker, Antje Helga Turon, Jean-Louis |
author_sort |
Penaud, Aurélie |
title |
Palaeohydrological changes over the last 50 ky in the central Gulf of Cadiz: complex forcing mechanisms mixing multi-scale processes |
title_short |
Palaeohydrological changes over the last 50 ky in the central Gulf of Cadiz: complex forcing mechanisms mixing multi-scale processes |
title_full |
Palaeohydrological changes over the last 50 ky in the central Gulf of Cadiz: complex forcing mechanisms mixing multi-scale processes |
title_fullStr |
Palaeohydrological changes over the last 50 ky in the central Gulf of Cadiz: complex forcing mechanisms mixing multi-scale processes |
title_full_unstemmed |
Palaeohydrological changes over the last 50 ky in the central Gulf of Cadiz: complex forcing mechanisms mixing multi-scale processes |
title_sort |
palaeohydrological changes over the last 50 ky in the central gulf of cadiz: complex forcing mechanisms mixing multi-scale processes |
publisher |
HAL CCSD |
publishDate |
2016 |
url |
https://hal-insu.archives-ouvertes.fr/insu-03678729 https://hal-insu.archives-ouvertes.fr/insu-03678729/document https://hal-insu.archives-ouvertes.fr/insu-03678729/file/bg-13-5357-2016.pdf https://doi.org/10.5194/bg-13-5357-2016 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland North Atlantic |
genre_facet |
Greenland North Atlantic |
op_source |
ISSN: 1726-4170 EISSN: 1726-4189 Biogeosciences https://hal-insu.archives-ouvertes.fr/insu-03678729 Biogeosciences, 2016, 13, pp.5357-5377. ⟨10.5194/bg-13-5357-2016⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/bg-13-5357-2016 insu-03678729 https://hal-insu.archives-ouvertes.fr/insu-03678729 https://hal-insu.archives-ouvertes.fr/insu-03678729/document https://hal-insu.archives-ouvertes.fr/insu-03678729/file/bg-13-5357-2016.pdf BIBCODE: 2016BGeo.13.5357P doi:10.5194/bg-13-5357-2016 |
op_rights |
http://creativecommons.org/licenses/by/ info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.5194/bg-13-5357-2016 |
container_title |
Biogeosciences |
container_volume |
13 |
container_issue |
18 |
container_start_page |
5357 |
op_container_end_page |
5377 |
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1766019844029808640 |
spelling |
ftunivnantes:oai:HAL:insu-03678729v1 2023-05-15T16:30:08+02:00 Palaeohydrological changes over the last 50 ky in the central Gulf of Cadiz: complex forcing mechanisms mixing multi-scale processes Penaud, Aurélie Eynaud, Frédérique Luise Voelker, Antje Helga Turon, Jean-Louis Domaines Océaniques (LDO) Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Observatoire des Sciences de l'Univers-Institut d'écologie et environnement-Centre National de la Recherche Scientifique (CNRS) Environnements et Paléoenvironnements OCéaniques (EPOC) Observatoire aquitain des sciences de l'univers (OASU) Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE) Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS) 2016 https://hal-insu.archives-ouvertes.fr/insu-03678729 https://hal-insu.archives-ouvertes.fr/insu-03678729/document https://hal-insu.archives-ouvertes.fr/insu-03678729/file/bg-13-5357-2016.pdf https://doi.org/10.5194/bg-13-5357-2016 en eng HAL CCSD European Geosciences Union info:eu-repo/semantics/altIdentifier/doi/10.5194/bg-13-5357-2016 insu-03678729 https://hal-insu.archives-ouvertes.fr/insu-03678729 https://hal-insu.archives-ouvertes.fr/insu-03678729/document https://hal-insu.archives-ouvertes.fr/insu-03678729/file/bg-13-5357-2016.pdf BIBCODE: 2016BGeo.13.5357P doi:10.5194/bg-13-5357-2016 http://creativecommons.org/licenses/by/ info:eu-repo/semantics/OpenAccess ISSN: 1726-4170 EISSN: 1726-4189 Biogeosciences https://hal-insu.archives-ouvertes.fr/insu-03678729 Biogeosciences, 2016, 13, pp.5357-5377. ⟨10.5194/bg-13-5357-2016⟩ [SDU]Sciences of the Universe [physics] info:eu-repo/semantics/article Journal articles 2016 ftunivnantes https://doi.org/10.5194/bg-13-5357-2016 2023-02-08T02:48:24Z International audience New dinoflagellate cyst (dinocyst) analyses were carried out at high resolution in core MD99-2339, retrieved from a contouritic field in the central part of the Gulf of Cadiz, for the Marine Isotope Stage (MIS) 3 interval, allowing for discussion of palaeohydrological changes over the last 50 ky in the subtropical NE Atlantic Ocean. Some index dinocyst taxa, according to their (palaeo)ecological significance, shed light on significant sea-surface changes. Superimposed on the general decreasing pattern of dinocyst export to the seafloor over the last 50 ky, paralleling the general context of decreasing aeolian dust fertilization, a complex variability in dinocyst assemblages was detected at the millennial timescale. Enhanced fluvial discharges occurred during Greenland Interstadials (GIs), especially GI 1, 8 and 12, while enhanced upwelling cell dynamics were suggested during the Last Glacial Maximum and Heinrich Stadials. Finally, during the early Holocene, and more specifically during the Sapropel 1 interval (around 7-9 ka BP), we evidenced a strong decrease in dinocyst fluxes, which occurred synchronously to a strong reduction in Mediterranean Outflow Water strength and which we attributed to an advection of warm and nutrient-poor subtropical North Atlantic Central Waters. Over the last 50 ky, our study thus allows for capturing and documenting the fine tuning existing between terrestrial and marine realms in North Atlantic subtropical latitudes, in response to not only the regional climate pattern but also monsoonal forcing interfering during precession-driven Northern Hemisphere insolation maxima. This mechanism, well expressed during the Holocene, is superimposed on the pervasive role of the obliquity as a first major trigger for explaining migration of dinocyst productive centres in the NE Atlantic margin to the subtropical (temperate) latitudes during glacial (interglacial) periods. Article in Journal/Newspaper Greenland North Atlantic Université de Nantes: HAL-UNIV-NANTES Greenland Biogeosciences 13 18 5357 5377 |