Iceberg production on Antarctica

Abstract

Structural failure of ice cliffs could potentially contribute significantly to major ice retreat of the Antarctic ice sheet. In the future, this could result in an increase of global mean sea level rise. We discuss two parametrisations for ice wastage due to ice cliff failure calving. We apply the parametrisations by implementing a module to the existing 3D Antarctic model ANICE. An analytical comparison between calving parametrisations favours a parametrisation from Schlemm and Levermann (2018) over a parametrisation from Pollard et al. (2015). Simulations that apply a sudden increase in temperature show that cliff failure calving has no significant influence during cold climate situations, but can contribute up to 11% of global sea level rises during warm climate situations. Applying ice shelf removal mechanisms show that ice sheets are especially vulnerable to cliff failure calving when ice shelves retreat. Cliff failure calving causes retreated ice sheets to recover more slowly and could reduce return rates by up to 38%. RCP enforced simulations imply 0.16 metres of additional global sea level rise due to cliff failure calving by 2500.