Melt-under-cutting and buoyancy-driven calving from tidewater glaciers : new insights from discrete element and continuum model simulations
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The simple calving laws currently used in ice sheet models do not adequately reflect the complexity and diversity of calving processes. To be effective, calving laws must be grounded in a sound understanding of how calving actually works. Here, we develop a new strategy for formulating calving laws, using a) the Helsinki Discrete Element Model (HiDEM) to explicitly model fracture and calving processes, and b) the continuum model Elmer/Ice to identify critical stress states associated with HiDEM calving events. A range of observed calving processes emerges spontaneously from HiDEM in response to variations in ice-front buoyancy and the size of subaqueous undercuts. Calving driven by buoyancy and melt undercutting is under-predicted by existing calving laws, but we show that the location and magnitude of HiDEM calving events can be predicted in Elmer/Ice from characteristic stress patterns. Our results open the way to developing calving laws that properly reflect the diversity of calving processes, and provide a framework for a unified theory of the calving process continuum.
Benn , D I , Åström , J , Zwinger , T , Todd , J , Nick , F M , Cook , S , Hulton , N R J & Luckman , A 2017 , ' Melt-under-cutting and buoyancy-driven calving from tidewater glaciers : new insights from discrete element and continuum model simulations ' Journal of Glaciology , vol 63 , no. 240 , JOG-17-0005 , pp. 691-702 . DOI: 10.1017/jog.2017.41
Journal of Glaciology
© The Author(s) 2017. This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited.
DescriptionThis work was funded by the ConocoPhillips Northern Area Program (CRIOS: Calving Rates and Impact on Sea Level) and the Nordic Research Council (SVALI: Stability and Variation of Arctic Land Ice and eSTICC: eScience Tools for Investigating Climate Change in northern high latitudes).
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