Title

A Large West Antarctic Ice Sheet Explains Early Neogene Sea-level Amplitude

Authors

J. W. Marschalek, Department of Earth Science and Engineering, Imperial College London, London, UK
L. Zurli, University of Siena
F. Talarico, University of Siena
Flierdt van de Flierdt, Department of Earth Science and Engineering, Imperial College London, London, UK
P. Vermeesch, University College London
A. Carter, University of London
F. Beny, Laboratoire d’Océanologie et de Géosciences, UMR 8187 CNRS/Univ Lille/ULCO, Villeneuve d’Ascq, France
V. Bout-Roumazeilles, Laboratoire d’Océanologie et de Géosciences, UMR 8187 CNRS/Univ Lille/ULCO, Villeneuve d’Ascq, France
F. Sangiorgi, Utrecht University
S. R. Hemming, Lamont-Doherty Earth Observatory of Columbia University Palisades
L. F. Pérez, British Antarctic Survey, Cambridge, UK
F. Colleoni, National Institute of Oceanography and Applied Geophysics – OGS
J. G. Prebble, GNS Science, Lower Hutt, New Zealand
T. E. van Peer, University College London
M. Perotti, University of Siena
A. E. Shevenell, University of South FloridaFollow
I. Browne, University of South Florida
D. K. Kulhanek, Texas A&M University
R. Levy, GNS Science, Lower Hutt, New Zealand
D. Harwood, University of Nebraska-Lincoln
N. B. Sullivan, University of Wisconsin-Madison
S. R. Meyers, University of Wisconsin-Madison
E. M. Griffith, Ohio State University
C.-D. Hillenbrand, British Antarctic Survey, Cambridge, UK
E. Gasson, University of Exeter
M. J. Siegert, Department of Earth Science and Engineering, Imperial College London, London, UK
B. Keisling, Lamont-Doherty Earth Observatory of Columbia University Palisades
K. J. Licht, Indiana University Purdue University Indianapolis
G. Kuhn, Alfred Wegener Institute
J. P. Dodd, Northern Illinois University
C. Boshuis, Utrecht University
L. De Santis, National Institute of Oceanography and Applied Geophysics – OGS
R. M. McKay, Victoria University of Wellington

Document Type

Article

Publication Date

2021

Keywords

Cryospheric science, Geochemistry, Palaeoclimate

Digital Object Identifier (DOI)

https://doi.org/10.1038/s41586-021-04148-0

Abstract

Early to Middle Miocene sea-level oscillations of approximately 40–60 m estimated from far-field records1–3 are interpreted to reflect the loss of virtually all East Antarctic ice during peak warmth2. This contrasts with ice-sheet model experiments suggesting most terrestrial ice in East Antarctica was retained even during the warmest intervals of the Middle Miocene4,5. 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. Variations in Miocene sea level can be explained by a large marine-based West Antarctic Ice Sheet.

Was this content written or created while at USF?

Yes

Citation / Publisher Attribution

Nature, v. 600, p. 450-455

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