Modelling the effects of topography on ice sheet erosion, Scotland

Abstract

The aim of this thesis is to consider the spatial variation in ice sheet erosion under former Scottish ice sheets. The emphasis of the research is on the pattern of ice sheet erosion at the regional scale, intermediate between that of individual landforms and an ice sheet as a whole. The basal thermal regime of the former ice sheet is calculated and the predicted pattern of basal temperaturesc omparedt o the observedp atterno f ice sheete rosion derived from fieldwork. This approachis usedt o test the hypothesist hat basal thermal regime is the crucial factor determining the ability of an ice sheet to erode its bed.

There are 5 specific objectives: (1) To calculate the basal thermal regime of a former Scottish ice sheet at its maximum assuming uniform sheet flow over the basal topography. (2) To calculate the basal thermal regime of a former Scottish ice sheet at its maximum taking into account the convergence and divergence of ice flow as it moves over the irregular topography. I (3) To map the distribution of landforms of glacial erosion from the centre to the periphery of the ice sheet to establish the regional pattern of erosion and the intensity of modification of the landscape by ice sheet erosion. (4)- To map the distribution of glacial and preglacial landforms at detailed field study sites and make estimates of minimum and maximum depths of ice sheet erosion in representative areas. (5) To compare the pattern of ice sheet erosion in the field with the modelled pattern of basal thermal regime in order to study the processes by which ice sheets modify landscapes.