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Millennial-scale variations of the Holocene North Atlantic mid-depth gyre inferred from radiocarbon and neodymium isotopes in cold water corals

dc.rights.licenseopenen_US
hal.structure.identifierGéosciences Paris Sud [GEOPS]
dc.contributor.authorCOLIN, Christophe
hal.structure.identifierLaboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] [LSCE]
hal.structure.identifierGéochrononologie Traceurs Archéométrie [GEOTRAC]
dc.contributor.authorTISNERAT-LABORDE, Nadine
hal.structure.identifierUniversiteit Utrecht / Utrecht University [Utrecht]
dc.contributor.authorMIENIS, Furu
hal.structure.identifierUniversiteit Gent = Ghent University [UGENT]
dc.contributor.authorCOLLART, Tim
hal.structure.identifierLaboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] [LSCE]
hal.structure.identifierGéochrononologie Traceurs Archéométrie [GEOTRAC]
dc.contributor.authorPONS-BRANCHU, Edwige
hal.structure.identifierGéosciences Paris Sud [GEOPS]
dc.contributor.authorDUBOIS-DAUPHIN, Quentin
hal.structure.identifierLaboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] [LSCE]
hal.structure.identifierGéochrononologie Traceurs Archéométrie [GEOTRAC]
dc.contributor.authorFRANK, Norbert
hal.structure.identifierLaboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] [LSCE]
hal.structure.identifierGéochrononologie Traceurs Archéométrie [GEOTRAC]
dc.contributor.authorDAPOIGNY, Arnaud
hal.structure.identifierLaboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] [LSCE]
dc.contributor.authorAYACHE, Mohamed
hal.structure.identifierEnvironnements et Paléoenvironnements OCéaniques [EPOC]
dc.contributor.authorSWINGEDOUW, Didier
hal.structure.identifierLaboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] [LSCE]
hal.structure.identifierModélisation du climat [CLIM]
dc.contributor.authorDUTAY, Jean-Claude
hal.structure.identifierEnvironnements et Paléoenvironnements OCéaniques [EPOC]
dc.contributor.authorEYNAUD, Frederique
IDREF: 144113570
hal.structure.identifierMorphodynamique Continentale et Côtière [M2C]
dc.contributor.authorDEBRET, Maxime
hal.structure.identifierLaboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] [LSCE]
hal.structure.identifierPaléocéanographie [PALEOCEAN]
dc.contributor.authorBLAMART, Dominique
hal.structure.identifierLaboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] [LSCE]
hal.structure.identifierGéochrononologie Traceurs Archéométrie [GEOTRAC]
dc.contributor.authorDOUVILLE, Eric
dc.date.accessioned2024-02-27T12:11:17Z
dc.date.available2024-02-27T12:11:17Z
dc.date.issued2019-05
dc.identifier.issn0277-3791en_US
dc.identifier.urihttps://oskar-bordeaux.fr/handle/20.500.12278/188454
dc.description.abstractEnVariations in North Atlantic Ocean mid-depth circulation during the Holocene are poorly understood. It is believed that they had a significant influence on the properties of water entering the Nordic Sea by redistributing heat and freshwater, potentially affecting deep-water formation and climate. To improve our knowledge of the NE Atlantic mid-depth circulation, radiocarbon and neodymium isotope analyses have been then carried out on precisely dated (U-Th) L. pertusa and M. oculata coral fragments from two sediment cores taken at ∼750 m water depth on the SW Rockall Trough margin. Cold-water coral (CWC) εNd values vary between −12.2 ± 0.3 and −16.6 ± 0.4 and result from variable contributions of unradiogenic mid-depth subpolar gyre (mid-SPG) water (∼-15) and more radiogenic Eastern North Atlantic Water (ENAW) (∼-11) which is transported northward to the Rockall Trough by boundary currents along the European margin. Increased coral εNd reflects a westward contraction of the mid-SPG water and a higher proportion of ENAW. The mid-Holocene (from 8.8 to 6.8 ka BP) is marked by unradiogenic coral εNd (from −16.6 ± 0.4 to −14.6 ± 0.5) indicating a greater eastward extension of the mid-SPG. This is followed by a shift from 6.8 to 5 ka BP toward more radiogenic εNd values (from −15.4 ± 0.3 to −13.3 ± 0.2) suggesting a westward contraction of the mid-SPG and a higher proportion of ENAW. The mid-Holocene long-term change in εNd is characterized by millennial variations of up to 2.5 epsilon units well marked during the Late Holocene, indicating that eastward extension of the mid-SPG coeval with warm periods in northern Europe (e.g. the Medieval Climatic Anomaly and the Roman Warm Period). Most of the CWC-derived Δ14C values match the global ocean values indicating that the water masses bathing the corals were generally well ventilated; the exceptions are a few short intervals of eastward extension of the mid-SPG, which are characterized by lower Δ14C during the late Holocene. We propose that these minor Δ14C fluctuations in the Rockall Trough may be related to local changes in the mixed layer depth or to variability in the advection of water from the Labrador Sea where deep convection gives rise to thermocline waters that are relatively depleted in terms of Δ14C.The eastward extension of the mid-SPG between 8.8 and 6.8 ka BP is associated with the Holocene climatic optimum, concurrent with a maximum strength of the Iceland-Scotland Overflow Water (ISOW), which is indicative of an increase in the Atlantic Meridional Overturning Circulation (AMOC). This period is followed by a transition in the North Atlantic circulation, which occurred around 6.8 ka BP, and coincides with the onset of Labrador Sea Water formation, a decrease of the ISOW strength and a contraction of the mid-SPG leading to a greater intrusion of saline subtropical water into the subpolar Atlantic.
dc.description.sponsorshipIPSL Climate graduate school - ANR-17-EURE-0006en_US
dc.description.sponsorshipLabEx Institut Pierre Simon Laplace (IPSL): Understand climate and anticipate future changes - ANR-10-LABX-0018en_US
dc.language.isoENen_US
dc.subjectPANOPLY
dc.subject.enPanoply
dc.subject.enCold-water corals
dc.subject.enRockall Trough
dc.subject.enHolocene
dc.subject.enNd isotopic composition
dc.subject.enradiocarbon
dc.subject.enNorth Atlantic gyre dynamics.
dc.title.enMillennial-scale variations of the Holocene North Atlantic mid-depth gyre inferred from radiocarbon and neodymium isotopes in cold water corals
dc.typeArticle de revueen_US
dc.identifier.doi10.1016/j.quascirev.2019.03.011en_US
dc.subject.halPlanète et Univers [physics]en_US
dc.subject.halPlanète et Univers [physics]/Sciences de la Terreen_US
dc.subject.halSciences de l'environnement/Biodiversité et Ecologieen_US
bordeaux.journalQuaternary Science Reviewsen_US
bordeaux.page93-106en_US
bordeaux.volume211en_US
bordeaux.hal.laboratoriesEPOC : Environnements et Paléoenvironnements Océaniques et Continentaux - UMR 5805en_US
bordeaux.institutionUniversité de Bordeauxen_US
bordeaux.institutionCNRSen_US
bordeaux.teamPALEOen_US
bordeaux.peerReviewedouien_US
bordeaux.inpressnonen_US
bordeaux.import.sourcehal
hal.identifierhal-02087629
hal.version1
hal.popularnonen_US
hal.audienceInternationaleen_US
hal.exportfalse
workflow.import.sourcehal
dc.rights.ccPas de Licence CCen_US
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