Fracture-induced softening for large-scale ice dynamics

Published: Dec 1, 2014 by The PISM Authors

Surface velocity, calculated fracture density, and modeled flow results for Filchner Ice Shelf.

Surface velocity, calculated fracture density, and modeled flow results for Filchner Ice Shelf.

Title Fracture-induced softening for large-scale ice dynamics
Authors T. Albrecht and A. Levermann
Venue The Cryosphere

Fracture processes within ice shelfs have been observed to reduce the retentive forces of the shelves on the Antarctic ice sheet. This paper adds a continuum representation of fractures, and their evolution, to PISM, and applies it to several major ice shelves in Antarctica. A key addition is the introduction of a higher-order scheme for advecting the two-dimensional fracture density field. Fractures and ice flow are coupled through a reduction of modeled ice viscosity proportional to the fracture density, so fracture-induced softening can feed back to cause added shear and self-amplified fracturing. The results of the simulations are compared to observations. Observed sharp across-flow velocity gradients in fracture-weakened regions are reproduced. This fracture-softening model is a basis for a future model of enhanced fracture-based calving.


Latest news

Version 1.2

We are pleased to announce the release of the Parallel Ice Sheet Model (PISM) v1.2.

MPI-M Hamburg, Germany: open postdoc for coupled atmosphere-ocean-ice sheet model

The Max Planck Institute for Meteorology (MPI-M) contributes to the BMBF project “From the Last Interglacial to the Anthropocene: Modeling a Complete Glacial Cycle” (PalMod,, which aims at simulating the climate from the peak of the last interglacial up to the present using comprehensive Earth System Models. Phase II of this project has an open position Postdoctoral Scientist (W073). The successful candidate will be part of a local team performing and analysing long-term transient simulations covering the last glacial and the transition into the Holocene with an interactively coupled atmosphere-ocean-ice sheet model. Additionally, the candidate will contribute to the continued development of this model. The model system consists of the MPI-Earth system model, the ice sheet model PISM, and the solid-earth model VILMA.

AWI PostDoc: Antarctic Ice Sheets in warming climates

Dr. Lohmann’s group at AWI is seeking a postdoc to work with PISM and the multi-scale Earth system model AWI-ESM. See