A large West Antarctic Ice Sheet explains early Neogene sea-level amplitude.

Autor: Marschalek JW; Department of Earth Science and Engineering, Imperial College London, London, UK. j.marschalek18@imperial.ac.uk., Zurli L; Department of Physical, Earth and Environmental Sciences, University of Siena, Siena, Italy., Talarico F; Department of Physical, Earth and Environmental Sciences, University of Siena, Siena, Italy., van de Flierdt T; Department of Earth Science and Engineering, Imperial College London, London, UK., Vermeesch P; Department of Earth Sciences, University College London, London, UK., Carter A; Department of Earth and Planetary Sciences, Birkbeck, University of London, London, UK., Beny F; Laboratoire d'Océanologie et de Géosciences, UMR 8187 CNRS/Univ Lille/ULCO, Villeneuve d'Ascq, France., Bout-Roumazeilles V; Laboratoire d'Océanologie et de Géosciences, UMR 8187 CNRS/Univ Lille/ULCO, Villeneuve d'Ascq, France., Sangiorgi F; Department of Earth Sciences, Marine Palynology and Paleoceanography, Utrecht University, Utrecht, the Netherlands., Hemming SR; Lamont-Doherty Earth Observatory of Columbia University Palisades, New York, NY, USA., Pérez LF; British Antarctic Survey, Cambridge, UK.; Geological Survey of Denmark and Greenland, Department of Marine Geology, Aarhus, Denmark., Colleoni F; National Institute of Oceanography and Applied Geophysics - OGS, Trieste, Italy., Prebble JG; GNS Science, Lower Hutt, New Zealand., van Peer TE; Department of Earth Sciences, University College London, London, UK.; National Oceanography Centre Southampton, University of Southampton Waterfront Campus, Southampton, UK., Perotti M; Department of Physical, Earth and Environmental Sciences, University of Siena, Siena, Italy., Shevenell AE; College of Marine Science, University of South Florida, St. Petersburg, FL, USA., Browne I; College of Marine Science, University of South Florida, St. Petersburg, FL, USA., Kulhanek DK; International Ocean Discovery Program, Texas A&M University, College Station, TX, USA.; Institute of Geosciences, Christian-Albrechts-University of Kiel, Kiel, Germany., Levy R; GNS Science, Lower Hutt, New Zealand.; Institute of Geosciences, Christian-Albrechts-University of Kiel, Kiel, Germany., Harwood D; Department of Earth and Atmospheric Sciences, University of Nebraska-Lincoln, Lincoln, NE, USA., Sullivan NB; Department of Geoscience, University of Wisconsin-Madison, Madison, WI, USA., Meyers SR; Department of Geoscience, University of Wisconsin-Madison, Madison, WI, USA., Griffith EM; School of Earth Sciences, Ohio State University, Columbus, OH, USA., Hillenbrand CD; British Antarctic Survey, Cambridge, UK., Gasson E; Centre for Geography and Environmental Sciences, University of Exeter, Cornwall, UK., Siegert MJ; Department of Earth Science and Engineering, Imperial College London, London, UK.; Grantham Institute, Imperial College London, London, UK., Keisling B; Lamont-Doherty Earth Observatory of Columbia University Palisades, New York, NY, USA., Licht KJ; Department of Earth Sciences, Indiana University Purdue University Indianapolis, Indianapolis, IN, USA., Kuhn G; Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany., Dodd JP; Department of Geology and Environmental Geosciences, Northern Illinois University, DeKalb, IL, USA., Boshuis C; Department of Earth Sciences, Marine Palynology and Paleoceanography, Utrecht University, Utrecht, the Netherlands., De Santis L; National Institute of Oceanography and Applied Geophysics - OGS, Trieste, Italy., McKay RM; Antarctic Research Centre, Victoria University of Wellington, Wellington, New Zealand.
Jazyk: angličtina
Zdroj: Nature [Nature] 2021 Dec; Vol. 600 (7889), pp. 450-455. Date of Electronic Publication: 2021 Dec 15.
DOI: 10.1038/s41586-021-04148-0
Abstrakt: Early to Middle Miocene sea-level oscillations of approximately 40-60 m estimated from far-field records 1-3 are interpreted to reflect the loss of virtually all East Antarctic ice during peak warmth 2 . This contrasts with ice-sheet model experiments suggesting most terrestrial ice in East Antarctica was retained even during the warmest intervals of the Middle Miocene 4,5 . Data and model outputs can be reconciled if a large West Antarctic Ice Sheet (WAIS) existed and expanded across most of the outer continental shelf during the Early Miocene, accounting for maximum ice-sheet volumes. Here we provide the earliest geological evidence proving large WAIS expansions occurred during the Early Miocene (~17.72-17.40 Ma). Geochemical and petrographic data show glacimarine sediments recovered at International Ocean Discovery Program (IODP) Site U1521 in the central Ross Sea derive from West Antarctica, requiring the presence of a WAIS covering most of the Ross Sea continental shelf. Seismic, lithological and palynological data reveal the intermittent proximity of grounded ice to Site U1521. The erosion rate calculated from this sediment package greatly exceeds the long-term mean, implying rapid erosion of West Antarctica. This interval therefore captures a key step in the genesis of a marine-based WAIS and a tipping point in Antarctic ice-sheet evolution.
(© 2021. The Author(s), under exclusive licence to Springer Nature Limited.)
Databáze: MEDLINE
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