February 2012

A macroscopic fracture-density field is introduced into PISM. Its evolution includes the initiation and growth of fractures as well as their advection with two-dimensional ice flow. To first approximation, fracture growth is assumed to depend on the spreading rate only, while fracture initiation is defined in terms of principal stresses. The inferred fracture-density fields compare well with observed elongate surface structures. The aim of this study is to introduce the field and investigate which of the observed surface structures can be reproduced by the simplest physically motivated fracture source terms.