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dc.rights.licenseopenen_US
dc.contributor.authorCIVEL-MAZENS, M.
dc.contributor.authorCIVEL-MAZENS, Matthieu
hal.structure.identifierEnvironnements et Paléoenvironnements OCéaniques [EPOC]
dc.contributor.authorCROSTA, Xavier
dc.contributor.authorCORTESE, G.
dc.contributor.authorMICHEL, E.
dc.contributor.authorMAZAUD, A.
hal.structure.identifierEnvironnements et Paléoenvironnements OCéaniques [EPOC]
dc.contributor.authorTHER, Olivier
dc.contributor.authorIKEHARA, M.
dc.contributor.authorITAKI, T.
dc.date.accessioned2023-11-22T09:35:17Z
dc.date.available2023-11-22T09:35:17Z
dc.date.issued2021-07-01
dc.identifier.issn0921-8181en_US
dc.identifier.urihttps://oskar-bordeaux.fr/handle/20.500.12278/186047
dc.description.abstractEnIn the Southern Ocean (SO), climate-driven latitudinal migrations of the Antarctic Circumpolar Current (ACC) frontal system impact large-scale ocean circulation and primary productivity. Latitudinal migrations may not have been identical in all SO basins due to the presence or absence of regional bathymetric obstacles. The Antarctic Polar Front (APF), defined by the 3–5 °C surface temperature range and the 2 °C subsurface temperature minimum at 200 m, is particularly important for nutrient redistribution and biodiversity, influencing the soft tissue carbon pump in the modern SO. However, previous assessments of its migrations in the past, mostly based on a single metric or indirect observations, were not always robust. Here, we combine a new proxy for subsurface temperature (sub-ST) reconstructions based on radiolarian assemblages (sub-STrad), with relative abundance variations of key radiolarian species, and sea-surface temperatures (SST) reconstructions, based on diatom assemblages (SSTdiat), to refine estimations of the past mean APF locations in the Kerguelen Plateau (KP) region. Data from three sediment cores on a south (55°S) to north (47°S) transect are used to trace the mean APF locations for three climate states, glacials, peak-interglacials and mild-interglacials. Our results suggest that the APF, presently located south of Kerguelen Islands, shifted by 6–7 degrees of latitude and was located north of the KP during all glacial periods of the last 360 kyrs. This suggests that the ACC major flow interacted less with the bottom topography relative to its modern counterpart, probably resulting in less mixing of the water column over and in the lee of the KP. We propose that this process participated in the isolation of Antarctic surface waters (AASW) and in the reduction of macro-nutrient supply, thus resulting in lower regional productivity. During the warmer-than-present early interglacial periods, the APF probably migrated south by ~5 degrees of latitude relative to its modern position, to pass through the Fawn Trough. Contrary to glacial periods, the APF was forced in an “S” shape while the ACC main flow was constrained against the northern tip of the KP. In this configuration, a stronger interaction between the ACC, its associated fronts, and topography is expected, resulting in more mixing of the water column over and east of the KP. Congruently, siliceous productivity was probably restrained to latitudes south of the Fawn Trough.
dc.language.isoENen_US
dc.subject.enAntarctic Circumpolar Current
dc.subject.enAntarctic Polar Fronts
dc.subject.enAtmospheric Temperature
dc.subject.enBacillariophyta
dc.subject.enBiodiversity
dc.subject.enBottom Topography
dc.subject.enFawn Trough
dc.subject.enFossil Assemblage
dc.subject.enFrench Southern Territories
dc.subject.enGeodesy
dc.subject.enGlacial Geology
dc.subject.enGlacial-Interglacial Cycle
dc.subject.enIndian Ocean
dc.subject.enInterglacial
dc.subject.enInterglacial Periods
dc.subject.enKerguelen Islands
dc.subject.enKerguelen Plateau
dc.subject.enLarge-Scale Ocean Circulations
dc.subject.enLatitudinal Gradient
dc.subject.enMixing
dc.subject.enNutrients
dc.subject.enOcean Currents
dc.subject.enRadiolaria
dc.subject.enRadiolaria (Protozoans)
dc.subject.enRegional Productivity
dc.subject.enRelative Abundance
dc.subject.enSea Surface Temperature
dc.subject.enSea Surface Temperature (Sst)
dc.subject.enSouthern Ocean
dc.subject.enSubsurface Temperature
dc.subject.enSurface Properties
dc.subject.enSurface Temperatures
dc.subject.enSurface Waters
dc.subject.enTopography
dc.title.enAntarctic Polar Front migrations in the Kerguelen Plateau region, Southern Ocean, over the past 360 kyrs
dc.typeArticle de revueen_US
dc.identifier.doi10.1016/j.gloplacha.2021.103526en_US
dc.subject.halSciences de l'environnementen_US
bordeaux.journalGlobal and Planetary Changeen_US
bordeaux.volume202en_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
hal.popularnonen_US
hal.audienceInternationaleen_US
hal.exportfalse
dc.rights.ccPas de Licence CCen_US
bordeaux.COinSctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.jtitle=Global%20and%20Planetary%20Change&rft.date=2021-07-01&rft.volume=202&rft.eissn=0921-8181&rft.issn=0921-8181&rft.au=CIVEL-MAZENS,%20M.&CIVEL-MAZENS,%20Matthieu&CROSTA,%20Xavier&CORTESE,%20G.&MICHEL,%20E.&rft.genre=article


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