Simulation of anisotropic ice flow and fabric evolution along the GRIP-GISP2 flowline, central Greenland

Abstract

A model for the anisotropic behaviour of polar ice and the evolution of its strain-induced anisotropy is applied to the flowline between GRIP and GISP2. The linear constitutive law for polycrystalline ice is derived from the uniform-stress model under the assumptions of a linear transversely isotropic behaviour of the ice single crystal and of an orthotropic fabric described by a continuous parameterized orientation-distribution function (ODF). The velocities and fabrics obtained for the observed flowline and bedrock geometry, assuming stationary flow, are compared to those measured at the ice-sheet surface and down the two boreholes.