Marine ice-cliff instability modeling shows mixed-mode ice-cliff failure and yields calving rate parameterization

Citation

Crawford AJ, Benn DI, Todd J, Åström JA, Bassis JN & Zwinger T (2021) Marine ice-cliff instability modeling shows mixed-mode ice-cliff failure and yields calving rate parameterization. Nature Communications, 12 (1), Art. No.: 2701. https://doi.org/10.1038/s41467-021-23070-7

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.

Keywords
Cryospheric science; Environmental impact

Journal
Nature Communications: Volume 12, Issue 1

• Marine ice-cliff instability modeling shows mixed-mode ice-cliff failure and yields calving rate parameterization