Dynamics of the ice-age Earth: Solid mechanics and fluid mechanics

Abstract

The global theory of the glacial isostatic adjustment process is employed to infer the thicknesses of the continental ice sheets that existed at Last Glacial Maximum 21000 calendar years before present. Further analyses allow the global ice thickness distribution to be mapped into a paleo-topography for the planet as a whole, a field that is of primary importance for the understanding, through the application of modern general circulation models, of the surface climate that was characteristic of this epoch of Earth history. Crucial to the success of this procedure is knowledge of the radial visco-elastic structure of the solid Earth. Given an accurate model of the topography of the planet at Last Glacial Maximum that includes the component associated with the distribution of land ice, together with a surface albedo mask which differentiates ice covered from non-ice-covered regions, we may proceed to simulate the climate at glacial maximum using a modem coupled atmosphere-ocean general circulation model. Recently obtained results of this program are described which include an initial assessment of the primary modes of climate variability that were characteristic of the glacial state.