Marine ice-cliff instability modeling shows mixed-mode ice-cliff failure and yields calving rate parameterization
Abstract
Marine ice-cliff instability could accelerate ice loss from Antarctica, and according to some model predictions could potentially contribute >1 m of global mean sea level rise by 2100 at current emission rates. Regions with over-deepening basins >1 km in depth (e.g., the West Antarctic Ice Sheet) are particularly susceptible to this instability, as retreat could expose increasingly tall cliffs that could exceed ice stability thresholds. Here, we use a suite of high-fidelity glacier models to improve understanding of the modes through which ice cliffs can structurally fail and derive a conservative ice-cliff failure retreat rate parameterization for ice-sheet models. Our results highlight the respective roles of viscous deformation, shear-band formation, and brittle-tensile failure within marine ice-cliff instability. Calving rates increase non-linearly with cliff height, but runaway ice-cliff retreat can be inhibited by viscous flow and back force from iceberg mélange.
Citation
Crawford , A , Benn , D I , Todd , J , Åström , J , Bassis , J & Zwinger , T 2021 , ' Marine ice-cliff instability modeling shows mixed-mode ice-cliff failure and yields calving rate parameterization ' , Nature Communications , vol. 12 , 2701 . https://doi.org/10.1038/s41467-021-23070-7
Publication
Nature Communications
Status
Peer reviewed
ISSN
2041-1723Type
Journal article
Description
This work is from the DOMINOS project, a component of the International Thwaites Glacier Collaboration (ITGC). DOMINOS is supported by the Natural Environment Research Council (NERC: Grant NE/S006605/1). This article represents ITGC Contribution No. ITGC-020. The model simulations were conducted with computational resources provided by NERC and PRACE.Collections
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