Textural and Crystal-Fabric Anisotropies and the Flow of Ice Masses

Abstract

Accurate modeling and prediction of glacier response requires a better understanding of the influence of physical anisotropies on creep. To investigate the effects of variations in the degree of preferred crystallographic orientation and ice crystal size on creep, 19 samples of anisotropic glacier ice were deformed in simple shear. Results indicate that the time required for ice samples to reach the minimum strain rate decreases as crystal size increases; an increase in crystal-fabric development from an isotropic fabric to one with a strong single maximum results in an enhancement of the minimum strain rate by a factor of 4; and a doubling of the crystal size results in about a ninefold increase in the minimum strain rate.