Three-dimensional modelling of calving processes on Johnsons Glacier, Livingston Island, Antarctica.

Abstract

Iceberg calving is an important mass loss mechanism from ice shelves and tidewater glaciers for many mid and high-latitude glaciers and ice caps, yet the process is not well represented in prognostic models of ice dynamics. Benn and others (2007) proposed a calving criterion appropriate for both grounded and floating glacier tongues or ice shelves. This criterion assumes that the calving is triggered by the downward propagation of transverse surface crevasses, near the calving front, as a result of the extensional stress regime. The crevasse depth is calculated following Nye (1957), assuming that the base of a field of closely spaced crevasses lies at a depth where the longitudinal tensile strain rate tending to open the crevasse equals the creep closure resulting from the ice overburden pressure.