Antarctic topography at the Eocene-Oligocene boundary

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TitleAntarctic topography at the Eocene-Oligocene boundaryAbstractWe present a reconstruction of the Antarctic topography at the Eocene-Oligocene (ca. 34. Ma) climate transition. This provides a realistic key boundary condition for modeling the first big Antarctic ice sheets at this time instead of using the present day bedrock topography, which has changed significantly from millions of years of tectonism and erosion. We reconstruct topography using a set of tools including ice sheet-erosion models, models of thermal subsidence and plate movement. Erosion estimates are constrained with offshore sediment volumes estimated from seismic stratigraphy. Maximum and minimum topographic reconstructions are presented as indicators of the range of uncertainty. Our results point to a significant upland area in the Ross Sea/Marie Byrd Land and Weddell Sea sectors. In addition, East Antarctic coastal troughs are much shallower than today due to the restoration of material that has been selectively eroded by the evolving ice sheets. Parts of East Antarctica have not changed since the E-O boundary because they were protected under non-erosive cold-based ice. The reconstructions provide a better-defined boundary condition for modeling that seeks to understand interaction between the Antarctic ice sheet and climate, along with more robust estimates of past ice volumes under a range of orbital settings and greenhouse gas concentrations. â"' 2011 Elsevier B.V.AcknowledgementsWe are grateful to the Scientific Committee for Antarctic Research and to the Antarctic Climate Evolution program for funding and to the ANTscape working group (www.antscape.org) for the discussions from which this paper was developed. We thank Graeme Eagles and an anonymous reviewer for their constructive criticism and encouraging comments. Stewart Jamieson was funded by the Natural Environmental Research Council UK. This material is based upon work supported by the National Science Foundation under Cooperative Agreement No. 0342484 through subawards administered and issued by the ANDRILL Science Management Office at the University of Nebraska-Lincoln, as part of the ANDRILL U.S. Science Support Program.

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1st AuthorWilson, D.AuthorWilson, D.Jamieson, S.Barrett, P.Leitchenkov, G.Gohl, K.Larter, R.Year2012JournalPalaeogeography, Palaeoclimatology, PalaeoecologyVolume335-336Pages24-34DOI10.1016/j.palaeo.2011.05.028URLhttps://www.scopus.com/inward/recor.....90dd377e04559d77602ccebb0Keywordsboundary conditionEocene-Oligocene boundaryice sheetnumerical modelreconstructiontopographyuncertainty analysis, AntarcticaRoss SeaSouthern OceanWeddell Sea, rank3Author KeywordsAntarcticaGlacial erosionReconstructionTectonicsTopography

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TypeArticleCitationWilson, D., Jamieson, S., Barrett, P., Leitchenkov, G., Gohl, K. and Larter, R. (2012) Antarctic topography at the Eocene-Oligocene boundary. Palaeogeography, Palaeoclimatology, Palaeoecology, 335-336(June): 24-34 doi:10.1016/j.palaeo.2011.05.028 IdentifierWilson2012cRelevancerank3