Abstract
This thesis details the application of numerical modelling techniques to simulate
erosion under ice sheets with the aim of better understanding the interrelationships
between glacial erosion, long-term landscape evolution and ice dynamics. A model is
developed that predicts patterns of basal erosion in a glaciologically sensible manner
and shows that 'fluvial' landscapes can become 'glacial' systems within 100 kyrs. By
simulating ice sheet growth and erosion over synthetic landscapes of varying form,
amplitude and wavelength the topographic characteristics that are most critical to the
evolution of ice dynamics, and to ongoing erosion are identified. The model is
applied to the solution of two puzzles regarding the interaction of ice, erosion and
landscape in Patagonia and Antarctica. In settings similar to Patagonia, glacial
erosion is shown to be able to drive large-scale change in ice dynamics on 10⁵ to 10⁶
year timescales. This goes some way to explaining the behaviour of the Patagonian
ice sheet since the 'Greatest Patagonian Glaciation', whereby ice extents reduce over
successive glacial cycles, contradicting patterns of global ice volume. In Antarctica,
the model is used to predict the pattern of long-term ice mass expansion and
associated patterns of landscape evolution. For the first time, predictions tied to ice
dynamics are made regarding the degree to which the Antarctic landscape has been
modified by ice as it expands from local to regional ice centres and then to a
continental scale ice sheet. Common themes throughout this thesis are that preglacial landscape geometry is a critical driver of the pattern of landscape evolution
under ice, and that erosion should no longer be considered a passive component of
any glacial system over timescales of 10⁵ and greater.
