The Darwin-Hatherton glacial system (DHGS) drains from the East Antarctic Ice Sheet (EAIS) and through the Transantarctic Mountains (TAM) before entering the Ross Embayment. Large ice-free areas covered in glacial sediments surround the DHGS, and at least five glacial drift sheets mark the limits of previous ice extent. The glacier belongs to a group of slow-moving EAIS outlet glaciers which are poorly understood. Despite this, an extrapolation of a glacial drift sheet boundary has been used to determine the thickness of the EAIS and the advanced West Antarctic Ice Sheet (WAIS) during the Last Glacial Maximum (LGM). In order to accurately determine the past and present contributions of the Antarctic ice sheets to sea level changes, these uncertainties should be reduced. This study aims to examine the present and LGM ice dynamics of the DHGS by combining newly acquired field measurements with a 3-D numerical ice sheet-shelf model. The fieldwork included a ground penetrating radar survey of ice thickness and surface velocity measurements by GPS. In addition, an extensive dataset of airborne radar measurements and meteorological recordings from automatic weather stations were made available. The model setup involved nesting a high-resolution (1 km) model of the DHGS within a lower resolution (20 km) all-Antarctic simulation. The nested 3-D modelling procedure enables an examination of the impact of changes of the EAIS and WAIS on the DHGS behaviour, and accounts for a complex glacier morphology and surface mass balance within the glacial system. The findings of this study illustrate the difference in ice dynamics between the Darwin and Hatherton Glaciers. The Darwin Glacier is up to 1500 m thick, partially warm-based, has high driving stresses (~150 kPa), and measured ice velocities increase from 20-30 m yr⁻¹ in the upper parts to ~180 m yr⁻¹ in the lowermost steepest regions, where modelled flow velocities peak at 330 m yr⁻¹. In comparison, the Hatherton Glacier is relatively thin (<900 m), completely cold-based, has low driving stresses (~85 kPa), and is likely to flow with velocities <10 m yr⁻¹ in most regions. It is inferred that the slow velocities with which the DHGS flows are a result of high subglacial mountains restricting ice flow from the EAIS, large regions of frozen basal conditions, low SMB and undulating bedrock topography. The model simulation of LGM ice conditions within the DHGS implies that the ice thickness of the WAIS has been significantly overestimated in previous reconstructions. Results show that the surface of the WAIS and EAIS away from the TAM would have been elevated 600-750 and 0-80 m above present-day levels, respectively, for the DHGS to reach what was inferred to represent the LGM drift sheet limit. Ultimately, this research contributes towards a better understanding of the dynamic behaviour of slow moving TAM outlet glaciers, and provides new insight into past changes of the EAIS and WAIS. This will facilitate more accurate quantifications of contributions of the WAIS and EAIS to changes in global sea level.

<p>Understanding climate-driven changes in global land-based ice volume is a critical component in our capability to predict how global sea level will rise as a consequence of the current human-driven climate change. At the last glacial maximum (LGM, which peaked around 20 ka), ephemeral ice sheets covered vast regions of the northern hemisphere while both the Greenland and Antarctic ice sheets were more extensive than at present. As global temperatures rose at the transition into the Holocene, driving the LGM deglaciation, eustatic sea level rose by approximately 125 m. The east Antarctic ice sheet (EAIS) is the largest ice sheet on Earth today, holding an ice volume equivalent to ca. 53 m rise in global sea level. Considering current trends in global climate, specifically rapidly increasing atmospheric CO₂ levels and global temperature, it is important to improve our understanding of how the EAIS will respond to global warming so that we can make better predictions of future sea level changes to guide community adaptation and planning efforts. Numerical ice sheet models which inform projections of future ice volume changes, and can, therefore, yield projections of sea level rise, rely on empirical data to test their ability to accurately represent former and present ice configurations. However, there is a general lack of data on the paleoglaciology of the EAIS along the western Dronning Maud Land (DML) margin. In order to address this situation, the paleoglaciology of western DML forms the focus of the work presented in this thesis.</p><p><b> </b></p><p>Together with collaborators within the MAGIC-DML consortium (Mapping, Measuring and Modelling Antarctic Geomorphology and Ice Change in Dronning Maud Land) that provides the funding for this MS project, the author has performed geomorphological mapping across western DML; an area of approximately 200,000 km². The results of the mapping presented in this thesis will provide the basis for a detailed glacial reconstruction of the region. The geomorphological mapping was completed almost entirely by remote sensing using very high-resolution (sub-meter in the panchromatic) WordView-2 and WorldView-3 (WV) satellite imagery, combined with ground validation studies during field work. Compared to Landsat products, the improved spatial resolution provided by WV imagery has fundamentally changed the scale and detail at which remote sensing based geomorphological mapping can be completed. The mapping presented here is focused on the glacial geomorphology of mountain summits and flanks that protrude through the ice sheet’s surface (nunataks). In our study area of western DML these nunatak surfaces make up <0.2 % of the total surface area, and the landforms mapped here are generally smaller than can be identified from Landsat products (30 m spatial resolution). The detail achieved in our mapping, across such a vast, remote area that presents numerous obstacles to accessibility highlights the benefits of utilizing the new VHR WV data. As such an evaluation of the WV data, as applied to geomorphological mapping is presented here together with our mapping of the glacial geomorphology of western DML. The results of which provides evidence of ice having overridden sites at all elevations across the entire study area; from the highest elevation inland nunataks that form the coast-parallel escarpment, to low-elevation emerging nunataks close to the coast. Hence from our studies of the glacial geomorphology of this region we can ascertain that, at some point in the glacial history of western DML, ice covered all of the mountain summits that are exposed today, indicating an ice sheet surface lowering of up to 700 m in some places.</p>