Low post-glacial rebound rates in the Weddell Sea due to Late Holocene ice- sheet readvance

Bradley, S.L.; Hindmarsh, R.C.A.; Whitehouse, P.L.; Bentley, M.J.; King, M.A.

doi:10.1016/j.epsl.2014.12.039

Low post-glacial rebound rates in the Weddell Sea due to Late Holocene ice- sheet readvance

Bradley, S.L.; Hindmarsh, R.C.A.; Whitehouse, P.L.; Bentley, M.J.; King, M.A.

Authors

S.L. Bradley

R.C.A. Hindmarsh

Professor Pippa Whitehouse pippa.whitehouse@durham.ac.uk
Professor

Professor Michael Bentley m.j.bentley@durham.ac.uk
Professor

M.A. King

Abstract

Many ice-sheet reconstructions assume monotonic Holocene retreat for the West Antarctic Ice Sheet, but an increasing number of glaciological observations infer that some portions of the ice sheet may be readvancing, following retreat behind the present-day margin. A readvance in the Weddell Sea region can reconcile two outstanding problems: (i) the present-day widespread occurrence of seemingly stable ice streams grounded on beds that deepen inland; and (ii) the inability of models of glacial isostatic adjustment to match present-day uplift rates. By combining a suite of ice loading histories that include a readvance with a model of glacial isostatic adjustment we report substantial improvements to predictions of present-day uplift rates, including reconciling one problematic observation of land sinking. We suggest retreat behind present grounding lines occurred when the bed was lower, and isostatic recovery has since led to shallowing, ice sheet re-grounding and readvance. The paradoxical existence of grounding lines in apparently unstable configurations on reverse bed slopes may be resolved by invoking the process of unstable advance, in accordance with our load modelling.

Citation

Bradley, S., Hindmarsh, R., Whitehouse, P., Bentley, M., & King, M. (2015). Low post-glacial rebound rates in the Weddell Sea due to Late Holocene ice- sheet readvance. Earth and Planetary Science Letters, 413, 79-89. https://doi.org/10.1016/j.epsl.2014.12.039

Journal Article Type	Article
Acceptance Date	Dec 17, 2014
Online Publication Date	Jan 16, 2015
Publication Date	Mar 1, 2015
Deposit Date	Dec 17, 2014
Publicly Available Date	Jan 15, 2015
Journal	Earth and Planetary Science Letters
Print ISSN	0012-821X
Publisher	Elsevier
Peer Reviewed	Peer Reviewed
Volume	413
Pages	79-89
DOI	https://doi.org/10.1016/j.epsl.2014.12.039
Keywords	Grounding line stability, Antarctic Ice sheet, Glacial isostatic adjustment, Uplift rate, Weddell Sea, Deglaciation.

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Copyright Statement
© 2014 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)