Long-term increase in Antarctic Ice Sheet vulnerability driven by bed topography evolution

Paxman, G.J.G.; Gasson, E.G.W.; Jamieson, S.S.R.; Bentley, M.J.; Ferraccioli, F.

doi:10.1029/2020gl090003

Long-term increase in Antarctic Ice Sheet vulnerability driven by bed topography evolution

Paxman, G.J.G.; Gasson, E.G.W.; Jamieson, S.S.R.; Bentley, M.J.; Ferraccioli, F.

Authors

Dr Guy Paxman guy.j.paxman@durham.ac.uk
Assistant Professor

E.G.W. Gasson

Professor Stewart Jamieson stewart.jamieson@durham.ac.uk
Professor

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

F. Ferraccioli

Abstract

Ice sheet behavior is strongly influenced by the bed topography. However, the effect of the progressive temporal evolution of Antarctica's subglacial landscape on the sensitivity of the Antarctic Ice Sheet (AIS) to climatic and oceanic change has yet to be fully quantified. Here we investigate the evolving sensitivity of the AIS using a series of data‐constrained reconstructions of Antarctic paleotopography since glacial inception at the Eocene‐Oligocene transition. We use a numerical ice sheet model to subject the AIS to schematic climate and ocean warming experiments and find that bed topographic evolution causes a doubling in ice volume loss and equivalent global sea level rise. Glacial erosion is primarily responsible for enhanced ice sheet retreat via the development of increasingly low‐lying and reverse sloping beds over time, particularly within near‐coastal subglacial basins. We conclude that AIS sensitivity to climate and ocean forcing has been substantially amplified by long‐term landscape evolution.

Citation

Paxman, G., Gasson, E., Jamieson, S., Bentley, M., & Ferraccioli, F. (2020). Long-term increase in Antarctic Ice Sheet vulnerability driven by bed topography evolution. Geophysical Research Letters, 47(20), Article e2020GL090003. https://doi.org/10.1029/2020gl090003

Journal Article Type	Article
Acceptance Date	Sep 30, 2020
Online Publication Date	Oct 20, 2020
Publication Date	2020-10
Deposit Date	Oct 1, 2020
Publicly Available Date	Oct 27, 2020
Journal	Geophysical Research Letters
Print ISSN	0094-8276
Publisher	Wiley
Peer Reviewed	Peer Reviewed
Volume	47
Issue	20
Article Number	e2020GL090003
DOI	https://doi.org/10.1029/2020gl090003

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Copyright Statement
©2020. The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.