Damage accelerates ice shelf instability and mass loss in Amundsen Sea Embayment

Lhermitte, Stef, Sun, Sainan, Shuman, Christopher, Wouters, Bert, Pattyn, Frank, Wuite, Jan, Berthier, Etienne and Nagler, Thomas (2020) Damage accelerates ice shelf instability and mass loss in Amundsen Sea Embayment. Proceedings of the National Academy of Sciences, 117 (40). pp. 24735-24741. ISSN 0027-8424

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Official URL: https://doi.org/10.1073/pnas.1912890117


Pine Island Glacier and Thwaites Glacier in the Amundsen Sea Embayment are among the fastest changing outlet glaciers in West Antarctica with large consequences for global sea level. Yet, assessing how much and how fast both glaciers will weaken if these changes continue remains a major uncertainty as many of the processes that control their ice shelf weakening and grounding line retreat are not well understood. Here, we combine multisource satellite imagery with modeling to uncover the rapid development of damage areas in the shear zones of Pine Island and Thwaites ice shelves. These damage areas consist of highly crevassed areas and open fractures and are first signs that the shear zones of both ice shelves have structurally weakened over the past decade. Idealized model results reveal moreover that the damage initiates a feedback process where initial ice shelf weakening triggers the development of damage in their shear zones, which results in further speedup, shearing, and weakening, hence promoting additional damage development. This damage feedback potentially preconditions these ice shelves for disintegration and enhances grounding line retreat. The results of this study suggest that damage feedback processes are key to future ice shelf stability, grounding line retreat, and sea level contributions from Antarctica. Moreover, they underline the need for incorporating these feedback processes, which are currently not accounted for in most ice sheet models, to improve sea level rise projections.

Item Type: Article
Additional Information: Funding information: S.L. was funded by the Dutch Research Council (NWO)/Netherlands Space Office Grant ALWGO.2018.043. C.S. was funded by the NASA Cryospheric Science Program. E.B. acknowledges support from the French Space Agency (CNES) through the Terre solide, Océan, Surfaces Continentales, Atmosphère (TOSCA) program. B.W. was funded by NWO VIDI Grant 016.Vidi.171.065. T.N. and J.W. acknowledge support from the European Space Agency through the Climate Change Initiative (CCI) program.
Uncontrolled Keywords: sea level rise, ice sheet modeling, remote sensing, Antarctica, glaciology
Subjects: F700 Ocean Sciences
F800 Physical and Terrestrial Geographical and Environmental Sciences
F900 Others in Physical Sciences
Department: Faculties > Engineering and Environment > Geography and Environmental Sciences
Depositing User: Rachel Branson
Date Deposited: 20 Sep 2021 13:33
Last Modified: 20 Sep 2021 13:45
URI: http://nrl.northumbria.ac.uk/id/eprint/47279

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