Orbital forcing of the East Antarctic ice sheet during the P

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TitleOrbital forcing of the East Antarctic ice sheet during the Pliocene and Early PleistoceneAbstractThe Pliocene and Early Pleistocene, between 5.3 and 0.8 million years ago, span a transition from a global climate state that was 2-3 deg C warmer than present with limited ice sheets in the Northern Hemisphere to one that was characterized by continental-scale glaciations at both poles. Growth and decay of these ice sheets was paced by variations in the EarthÅ› orbit around the Sun. However, the nature of the influence of orbital forcing on the ice sheets is unclear, particularly in light of the absence of a strong 20,000-year precession signal in geologic records of global ice volume and sea level. Here we present a record of the rate of accumulation of iceberg-rafted debris oshore from the East Antarctic ice sheet, adjacent to the Wilkes Subglacial Basin, between 4.3 and 2.2 million years ago. We infer that maximum iceberg debris accumulation is associated with the enhanced calving of icebergs during ice-sheet margin retreat. In the warmer part of the record, between 4.3 and 3.5 million years ago, spectral analyses show a dominant periodicity of about 40,000 years. Subsequently, the powers of the 100,000-year and 20,000-year signals strengthen. We suggest that, as the Southern Ocean cooled between 3.5 and 2.5 million years ago, the development of a perennial sea-ice field limited the oceanic forcing of the ice sheet. After this threshold was crossed, substantial retreat of the East Antarctic ice sheet occurred only during austral summer insolation maxima, as controlled by the precession cycle. Copyright 2014 Macmillan Publishers Limited. All rights reserved.AcknowledgementsThis research used samples and data provided by the Integrated Ocean Drilling Program (IODP). The IODP is sponsored by the US National Science Foundation (NSF) and participating countries under the management of Joint Oceanographic Institutions. Financial support for this study was provided to T.N. and R.M. from the Royal Society of New Zealand Marsden Fund Contract VUW0903, and Rutherford Discovery Fellowship (RDF-13-VUW-003) to R.M. Additional support was provided by the Ministry of Science and Innovation (Grant CTM-2011-24079) to C.E. and by MEXT to F.J.J-E., and by the US NSF (Grant OCE-1003603) to S.R.M. and US NSF (Grant OCE-1202632) to M.E.R.Funding DetailsOCE-1003603, NSF, National Science Foundation; OCE-1202632, NSF, National Science Foundation

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1st AuthorPatterson, M.AuthorPatterson, M.McKay, R.Naish, T.Escutia, C.Jimenez-Espejo, F.Raymo, M.Meyers, S.Tauxe, L.Brinkhuis, H.Klaus, A.Fehr, A.Bendle, J.Bijl, P.Bohaty, S.Carr, S.Dunbar, R.Flores, J.Gonzalez, J.Hayden, T.Iwai, M.Katsuki, K.Kong, G.Nakai, M.Olney, M.Passchier, S.Pekar, S.Pross, J.Riesselman, C.RÃƒÂ¶hl, U.Sakai, T.Shrivastava, P.Stickley, C.Sugasaki, S.Tuo, S.Van De Flierdt, T.Welsh, K.Williams, T.Yamane, M.Year2014JournalNature GeoscienceVolume7Number11Pages841-847DOI10.1038/ngeo2273URLhttps://www.scopus.com/inward/recor.....659efb5812214dd621b7f6cd6Keywordsglacial debrisglaciationglobal climateice sheeticebergorbital forcingPleistocenePliocene, Antarctic Ice SheetAntarcticaEast Antarctic Ice SheetEast Antarctica, rank1

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TypeArticleCitationPatterson, M., McKay, R., Naish, T., Escutia, C., Jimenez-Espejo, F., Raymo, M., Meyers, S., Tauxe, L., Brinkhuis, H., Klaus, A., Fehr, A., Bendle, J., Bijl, P., Bohaty, S., Carr, S., Dunbar, R., Flores, J., Gonzalez, J., Hayden, T., Iwai, M., Katsuki, K., Kong, G., Nakai, M., Olney, M., Passchier, S., Pekar, S., Pross, J., Riesselman, C., Röhl, U., Sakai, T., Shrivastava, P., Stickley, C., Sugasaki, S., Tuo, S., Van De Flierdt, T., Welsh, K., Williams, T. and Yamane, M. (2014) Orbital forcing of the East Antarctic ice sheet during the Pliocene and Early Pleistocene. Nature Geoscience, 7(11): 841-847 doi:10.1038/ngeo2273 IdentifierPatterson2014Relevancerank1