Influence of non-uniform temperature distribution on the steady motion of ice sheets

• Published in: Journal of Fluid Mechanics
• Main Authors: Morland, L. W., Smith, G. D.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 1984
• Subjects: Mechanical Engineering; Mechanics of Materials; Condensed Matter Physics; Applied Mathematics; Ice Sheet
• Online Access: http://dx.doi.org/10.1017/s0022112084000537; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022112084000537

The plane steady flow of a grounded ice sheet is analysed under the assumption that the ice behaves as a nonlinearly viscous fluid with a strongly temperature-dependent rate factor. It is supposed that the accumulation/ablation distribution on the (unknown) free surface is prescribed, and that there is a given basal sliding condition connecting the tangential velocity, tangential traction and normal pressure. The basal boundary is defined as the smooth contour which describes the mean topography viewed on the ice-sheet lengthscale, and is assumed to have small slope. The perturbation analysis which reduces the isothermal or constant rate factor equations to an ordinary differential equation for the leading-order profile is now extended with similar success to the non-isothermal problem when the temperature distribution is prescribed. That is, the thermomechanically coupled energy balance is not solved, but families of temperature distributions qualitatively compatible with observed patterns are adopted to exhibit the effects of significant creep-rate variation with temperature.