georefid:2012-087076SEDIS Publication Catalogue

ana.macario@awi.de

http://sedis.iodp.org/pub-catalogue/informationpointOfContact2013-07-08T00:00:00Zhttp://sedis.iodp.org/pub-catalogue/index.php?id=10.1016/j.quascirev.2011.03.0172011-01-01publicationgeorefid:2012-087076doi:10.1016/j.quascirev.2011.03.017Guihou, AbelCNRS-CEA-Universite de Versailles Saint-Quentin-en-Yvelines, Laboratoire des Sciences du Climat et de l'Environnement, Gif dur Yvette, FranceauthorPichat, SylvainEcole Normale Superieure de Lyon, FranceauthorGovin, AlineLaboratorio Nacional de Energia e Geologia, PortugalauthorNave, SilviaauthorMichel, ElisabethauthorDuplessy, Jean-ClaudeauthorTelouk, PhilippeauthorLabeyrie, LaurentauthorElsevier, InternationalpublisherdocumentHardcopyQuaternary Science Reviews30 (13-14)1576-1582The Atlantic Meridional Overturning Circulation (AMOC) is a key feature of the climate system. However, its role during climate change is still poorly constrained particularly during an Interglacial to Glacial climate transition and the associated global cooling. We present here the first reconstruction of the evolution of the vertical structure of the rate of the AMOC from the Last Interglaciation to the subsequent glaciation (128,000-60,000 years ago) based on sedimentary ( (super 231) Pa/ (super 230) Th) records. We show a deep AMOC during the interglacial warmth Marine Isotope Stage (MIS) 5.5 and a shallower glacial one during glacial MIS 4. The change between these two patterns occurred mostly during the glacial inception, i.e. the transition from MIS 5.5 to MIS 5.4. Our data show that AMOC was enhanced during this latter transition as a consequence of a large increase of the overturning rate of the Intermediate Waters, above 2500 m. We suggest that this AMOC pattern required a reinforced Gulf Stream-North Atlantic Current system that ultimately supported ice-sheet growth by providing heat and moisture to the Northern high latitudes. From MIS 5.4 to MIS 5.1, the AMOC was broadly continuous below 2000 m and supported periods of ice-sheet growth. As a result, a glacial AMOC is triggered at the beginning of MIS 4 due to the extension of ice-sheet and the subsequent reorganization of deep-water formation. This study highlights the role of intermediate waters as a major player during climate change. Abstract Copyright (2011) Elsevier, B.V.completedQuaternary geologyIsotope geochemistryactinidesAtlantic Meridional Overturning CirculationAtlantic OceanCenozoicglaciationisotopesLeg 162marine environmentmarine sedimentsmetalsMIS 4MIS 5North Atlanticocean circulationOcean Drilling ProgramODP Site 980Pa-231Pa-231/Th-230paleo-oceanographypaleoclimatologypaleoenvironmentPleistoceneprotactiniumQuaternaryradioactive isotopesRockall BanksedimentsTh-230thoriumupper Pleistoceneurn:org.iodp:exp:162urnlargerWorkCitationcampaignurn:org.iodp:exp:162:site:980urnlargerWorkCitationstudyurn:org.iodp:exp:162urnlargerWorkCitationcampaignEnglishgeoscientificInformation-40.0000-10.100037.050055.2906Supplemental information/data is available in the online version of this article; includes appendix