Antarctic ice shelf disintegration triggered by sea ice loss and ocean swell

Published online 13 June 2018 Understanding the causes of recent catastrophic ice shelf disintegrations is a crucial step towards improving coupled models of the Antarctic Ice Sheet and predicting its future state and contribution to sea-level rise. An overlooked climate-related causal factor is reg...

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Bibliographic Details
Published in:Nature
Main Authors: Massom, R., Scambos, T., Bennetts, L., Reid, P., Squire, V., Stammerjohn, S.
Format: Article in Journal/Newspaper
Language:English
Published: Nature Publishing Group 2018
Subjects:
Online Access:http://hdl.handle.net/2440/115349
https://doi.org/10.1038/s41586-018-0212-1
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Summary:Published online 13 June 2018 Understanding the causes of recent catastrophic ice shelf disintegrations is a crucial step towards improving coupled models of the Antarctic Ice Sheet and predicting its future state and contribution to sea-level rise. An overlooked climate-related causal factor is regional sea ice loss. Here we show that for the disintegration events observed (the collapse of the Larsen A and B and Wilkins ice shelves), the increased seasonal absence of a protective sea ice buffer enabled increased flexure of vulnerable outer ice shelf margins by ocean swells that probably weakened them to the point of calving. This outer-margin calving triggered wider-scale disintegration of ice shelves compromised by multiple factors in preceding years, with key prerequisites being extensive flooding and outer-margin fracturing. Wave-induced flexure is particularly effective in outermost ice shelf regions thinned by bottom crevassing. Our analysis of satellite and ocean-wave data and modelling of combined ice shelf, sea ice and wave properties highlights the need for ice sheet models to account for sea ice and ocean waves. Robert A. Massom, Theodore A. Scambos, Luke G. Bennetts, Phillip Reid, Vernon A. Squire and Sharon E. Stammerjohn