Classification of different calving modes
Fracture of ice is an inherently discontinuous process and consequently difficult to be included in continuum ice-flow models. There are existing models that deal with the physics of fracture, with the drawback of the demand for high spatial (in the size of the cracks) and temporal (spatial scales divided by speed of sound) resolution. In this paper the authors develop a new strategy for formulating calving laws,using a model of the latter kind, the Helsinki Discrete Element Model (HiDEM) to explicitly model fracture and calving. Simultaneously, the Elmer/Ice is applied to the same geometries to identify critical stress states that can be linked to computed calving events in HiDEM. The final goal is to develop improved calving laws for continuum models, as in last consequence only continuum models are capable to cover ice dynamics exceeding a few hours. Usually, calving induced by buoyancy and undercutting is under-represented in existing continuum calving laws. This study helps to identify stress states from a full Stokes model (Elmer/Ice) that can help to indicate characteristic stress/strain patterns that would be input for improved calving laws in future.
Read more: Benn, D.I., J. Åström, T. Zwinger, J. Todd, F.M. Nick, S. Cook, N.R.J. Hulton, and A. Luckman, 2017. Melt-under-cutting and buoyancy-driven calving from tidewater glaciers: new insights from discrete element and continuum model simulations, Journal of Glaciology, 1-12, doi:10.1017/jog.2017.41.