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dc.rights.licenseopenen_US
hal.structure.identifierInstituto Andaluz de Ciencias de la Tierra [IACT]
dc.contributor.authorROMERO, O.E.
hal.structure.identifierEnvironnements et Paléoenvironnements OCéaniques [EPOC]
dc.contributor.authorCROSTA, Xavier
hal.structure.identifierRoyal Netherlands Institute for Sea Research [NIOZ]
dc.contributor.authorKIM, J.-H.
hal.structure.identifierUniversity of Edinburgh [Edin.]
dc.contributor.authorPICHEVIN, L.
hal.structure.identifierCentre Européen de Recherche et d'Enseignement des Géosciences de l'Environnement [CEREGE]
dc.contributor.authorCRESPIN, J.
dc.date.accessioned2024-06-06T12:14:30Z
dc.date.available2024-06-06T12:14:30Z
dc.date.issued2015-02
dc.identifier.issn0921-8181en_US
dc.identifier.urihttps://oskar-bordeaux.fr/handle/20.500.12278/200314
dc.description.abstractEnAlthough productivity variations in coastal upwelling areas are mostly attributed to changes in wind strength, productivity dynamics in the Benguela Upwelling System (BUS) is less straightforward due to its complex atmospheric and hydrographic settings. In view of these settings, past productivity variations in the BUS can be better investigated with downcore sediments representing different productivity regimes. In this study, two sediment cores retrieved at ca. 25°-26°S in the BUS and representing different productivity regimes were studied. By using micropaleontological, geochemical and temperature proxies measured on core MD96-2098, recovered at 2910 m water depth in the bathypelagic zone at 26°S off Namibia, variations of filament front location, productivity and temperature in the central BUS over the past 70 kyr were reconstructed. The comparison with newly-generated alkenone-based sea-surface temperature (SST) and previously obtained data at site GeoB3606-1 (~ 25°S; ca. 50 km shoreward from MD96-2098) allowed the recognition of four main phases: (1) upwelling front above the mid slope (70 kyr-44 kyr), (2) seaward displacement of the upwelling front beyond the mid slope (44 kyr-31 kyr), (3) main upwelling front over the hemipelagial (31 kyr-19 kyr), and (4) shoreward contraction of the upwelling filament, and decreased upwelling strength over most of the uppermost bathypelagic (19 kyr-6 kyr). The latitudinal migration of the Southern Hemisphere westerlies and the consequent contractions and expansions of the subpolar gyre played a significant role in millennial and submillennial variability of SST off Namibia. The strength of the southeasterly trade winds, rapid sea-level variations and the equatorward leakage of Antarctic silicate might have acted as amplifiers. Although late Quaternary variations of productivity and upwelling intensity in eastern boundary current systems are thought to be primarily linked to the variability in wind stress, this multi-parameter reconstruction shows that interplaying mechanisms defined the temporal variation pattern of the filament front migrations and the diatom production off Namibia during the past 70 kyr.
dc.language.isoENen_US
dc.subject.enMillennial and submillennial time scale
dc.subject.enDiatoms
dc.subject.enBenguela
dc.subject.enProductivity
dc.subject.enSea-surface temperature
dc.subject.enSW Atlantic
dc.subject.enUpwelling filaments
dc.title.enRapid longitudinal migrations of the filament front off Namibia (SE Atlantic) during the past 70 kyr
dc.typeArticle de revueen_US
dc.identifier.doi10.1016/j.gloplacha.2014.12.001en_US
dc.subject.halPlanète et Univers [physics]/Océan, Atmosphèreen_US
dc.subject.halPlanète et Univers [physics]/Sciences de la Terre/Océanographieen_US
dc.subject.halPlanète et Univers [physics]/Sciences de la Terre/Climatologieen_US
bordeaux.journalGlobal and Planetary Changeen_US
bordeaux.page1-12en_US
bordeaux.volume125en_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-02105566
hal.version1
hal.popularnonen_US
hal.audienceInternationaleen_US
hal.exportfalse
workflow.import.sourcehal
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=2015-02&rft.volume=125&rft.spage=1-12&rft.epage=1-12&rft.eissn=0921-8181&rft.issn=0921-8181&rft.au=ROMERO,%20O.E.&CROSTA,%20Xavier&KIM,%20J.-H.&PICHEVIN,%20L.&CRESPIN,%20J.&rft.genre=article


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