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100,000 Years of African monsoon variability recorded in sediments of the Nile margin

dc.rights.licenseopenen_US
dc.contributor.authorREVEL, Marie
hal.structure.identifierEnvironnements et Paléoenvironnements OCéaniques [EPOC]
dc.contributor.authorDUCASSOU, Emmanuelle
hal.structure.identifierEnvironnements et Paléoenvironnements OCéaniques [EPOC]
dc.contributor.authorGROUSSET, Francis
dc.contributor.authorBERNASCONI, S. M.
dc.contributor.authorMIGEON, S.
dc.contributor.authorREVILLON, S.
dc.contributor.authorMASCLE, J.
dc.contributor.authorMURAT, A.
hal.structure.identifierEnvironnements et Paléoenvironnements OCéaniques [EPOC]
dc.contributor.authorZARAGOSI, Sebastien
IDREF: 189039159
dc.contributor.authorBOSCH, Delphine
dc.date.accessioned2024-10-25T08:12:15Z
dc.date.available2024-10-25T08:12:15Z
dc.date.issued2010-01-01
dc.identifier.issn0277-3791en_US
dc.identifier.urihttps://hal.archives-ouvertes.fr/hal-00496481
dc.identifier.urioai:crossref.org:10.1016/j.quascirev.2010.02.006
dc.identifier.uriftartxiker:oai:HAL:hal-00496481v1
dc.identifier.uriorcid:0000-0001-7672-8856:10.1016/j.quascirev.2010.02.006
dc.identifier.urihttps://oskar-bordeaux.fr/handle/20.500.12278/202799
dc.description.abstractEnMultiproxy analyses were performed on core MS27PT recovered in hemipelagic sediments deposited on the Nile margin in order to reconstruct Nile River palaeohydrological fluctuations during the last 100,000 years. The strontium and neodymium isotope composition of the terrigenous fraction and the major element distribution reveal large and abrupt changes in source, oscillating between a dominant aeolian Saharan contribution during arid periods and a dominant Nile River contribution during pluvial periods. Iron content shows a strong correlation with strontium and neodymium isotopes. This allows the use of a high-resolution continuous Fe record as a proxy of Blue Nile sediment input over the last 100,000 years. The detailed Fe record, with approximately 10 years resolution during pluvial periods, is consistent with subtropical African records of well-dated lake level fluctuations and thus constitutes a first continuous high resolution record of the East African monsoon regime intensity over Ethiopia.;The detailed Fe record shows the two main known pluvial periods attributed to strengthening of the African monsoon over Ethiopia, the Nabtian period from 14 to 8 ka cal BP and the Saharan period from 98 to 72 ka BR For the first time, the last glacial period (Marine Isotope Stage (MIS) 2,3 and 4) is documented with a continuous record showing large oscillations between high and low East African palaeo-monsoon regimes.;The end of the Nabtian period occurred at 8 ka in core MS27PT, i.e. much earlier than on the East Equatorial African region where it ended around 5.5 ka. We interpret this as evidence that the southward shift of the rain belt occurred 3000 years earlier over the Eastern Ethiopian Highland and propose that the gradual southward migration of the rain belt was associated with highly variable intensity and longer rainy seasons from 8 to 5 ka. During the last glacial period, two wet periods are present around 60-50 ka BP and 38-30 ka BP. These two humid periods are in phase with the rise of atmospheric CH4 concentrations suggesting that wetland tropical African area was one of the sources of the atmospheric CH4 during the MIS 3. During the Last Glacial Maximum and MIS 4, high Saharan aeolian influxes in phase with records of aeolian dust deposited in East Antarctica are documented. This study highlights the importance of reconstructions of monsoon rainfall fluctuation at high temporal resolution to better understand the link between low- and high-latitude climate variability at millennial timescales.
dc.language.isoENen_US
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dc.title.en100,000 Years of African monsoon variability recorded in sediments of the Nile margin
dc.typeArticle de revueen_US
dc.identifier.doi10.1016/j.quascirev.2010.02.006en_US
dc.subject.halSciences de l'environnementen_US
bordeaux.journalQuaternary Science Reviewsen_US
bordeaux.page1342-1362en_US
bordeaux.volume29en_US
bordeaux.hal.laboratoriesEPOC : Environnements et Paléoenvironnements Océaniques et Continentaux - UMR 5805en_US
bordeaux.issue11-12en_US
bordeaux.institutionUniversité de Bordeauxen_US
bordeaux.institutionCNRSen_US
bordeaux.teamGEOLSEDen_US
bordeaux.peerReviewedouien_US
bordeaux.inpressnonen_US
bordeaux.import.sourcedissemin
hal.popularnonen_US
hal.audienceInternationaleen_US
hal.exportfalse
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dc.rights.ccPas de Licence CCen_US
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