The influence of seasonal influx of supraglacial meltwater on basal water pressures and consequent changes in ice surface velocity has been a focus of research spanning over three decades. With a need to better include glacial hydrology within models of ice sheet evolution, the ability to predict where and when meltwater reaches the subglacial system is paramount for understanding the dynamics of large Arctic ice masses. The response of ice velocities to melt production suggests efficient transmission of meltwater from the supraglacial to subglacial hydrologic systems, and it has been shown that build-ups of stored meltwater in supraglacial lakes can force crevasse penetration through hundreds of metres of ice. This thesis presents a new modelling routine for prediction of moulin formation and delivery of meltwater to the ice-bed interface. Temporal and spatial patterns of moulin formation and drainage of supraglacial lakes are presented, and quantitative controls on crevasse propagation are investigated through a series of sensitivity tests. _J .' . The model is applied to two glacial catchments: the Croker Bay catchment of the Devon Ice Cap in High Arctic Canada; and the Leverett glacier catchment of the Greenland Ice Sheet. Through model application to these sites, sensitivities to crevasse surface dimensions, ice tensile strength, ice fracture toughness and air temperatures are investigated. Model predictions of moulin formation and melt transfer are compared with field observations and remotely sensed data, including ice surface velocities, proglacial discharge, dynamic flow regimes, and visible surface features. The inclusion of spatially distributed points of meltwater delivery to the 'subglacial system is imperative to fully understand the behaviour of the subglacial drainage system. Furthermore, dynamic response to future climatic change and melt scenarios, and the evolution of ice masses, cannot be fully understood without first understanding the glacial hydrologic processes driving many of these changes.

A thesis submitted to the Faculty of Science, University of the Witwatersrand, in fulfillment of the requirements for the degree of Doctor of Philosophy Johannesburg, 2012. / A variety of mass movement landforms occur in the southern Drakensberg, South Africa, and whilst a number of studies on individual landforms have been conducted, regional scale assessments of the Ukhahlamba Drakensberg Transfrontier Park have been relatively limited. Mass movement has been defined as the downward and outward movement of slope-forming material under the influence of a transporting agent such as water, air, ice or snow (Goudie, 2004). This includes landforms such as landslides, debris flows, terracettes, solifluction lobes and rockfall. Although two landslide risk assessments have been conducted in the region, one was site specific and focussed on shallow, translational slides (Bijker, 2001), whilst the other was at a much larger regional scale and focused on large palaeo-mass movements (Singh, 2008). Numerous international mass movement classifications have been developed over the years, and one of the primary aims of this research is to develop a classification for mass movement landforms within a southern African context. A number of mass movement landforms were identified, measured and mapped in the field to acquire a better understanding of how the landforms originate. This classification was then further adapted to facilitate the identification of mass movement landforms from orthophotos. Aerial photo interpretation techniques were used to map three terrace-type mass movement landforms and four shear-type mass movement landforms in the Garden Castle State Forest of the Ukhahlamba Drakensberg Transfrontier Park. A further level of detail was added to the classification by ascribing environmental conditions to the different landform types. A Geographic Information System was used to collate and generate spatial information which could be added to the landforms in the mass movement inventory. These were then analysed using univariate and multivariate statistical modelling. Histograms, as well as an area-weighted frequency distribution, were used to describe the landforms and then hierarchical partitioning was used to identify the environmental variables associated with each type of landform. One main environmental variable was identified for each type of mass movement. Logistic regression was then used to create probability maps for each type of landform. An average of 30% of the study area has a medium to very high likelihood of developing mass movements, although this percentage varies for each type, whilst rock movement deposits are predicted to occupy more than 80% of the study area. Gradient, altitude and lithology were selected most frequently by the statistical models as influencing landform distribution, whilst distance to a rock exposure had the strongest influence on the location of rock movement deposits. Aspect was selected least frequently by hierarchical partitioning which raises questions about the influence of aspect on valley asymmetry. Various models have been developed which describe slope development in the Drakensberg with reference to slope aspect, however the results of this study suggest that other environmental factors may be more important and that slope development is a complex process.

Thesis (Ph. D.)--University of Canterbury, 2009. / Typescript (photocopy). Includes bibliographical references. Also available via the World Wide Web.

The objective of this study is to reconstruct the history of glaciation from the start of Fraser (Late Wisconsinan) Glaciation to the end of deglaciation, for three areas in the Cascade Mountains. The Cascade Mountains are located between the Coast Mountains and the Interior Plateau in southwestern British Columbia. The Coast Mountains were glaciated by mountain glaciation followed by frontal retreat, whereas the Interior Plateau underwent ice sheet glaciation followed by downwasting and stagnation. The Cascades were supposed to have undergone a style of glaciation transitional between these two. Terrain mapping on air photographs followed by field checking was used to locate surficial materials and landforms indicative of glaciation style and pattern. All three study areas were glaciated by mixed mountain and ice sheet glaciation. At the start of Fraser Glaciation, alpine and valley glaciers formed around higher summits as occurred in the Coast Mountains. At the glacial maximum the entire area was covered by the Cordilleran Ice Sheet. Deglaciation was largely by continuous downvalley retreat of active glaciers, contrasting with downwasting and stagnation in the Interior Plateau, and frontal retreat in the Coast Mountains. The scarcity of fresh moraines in the cirques suggests that, unlike in the Coast Mountains, most cirque glaciers were not active at the end of glaciation. Only the highest north facing cirques remained above the local snowline throughout deglaciation and, as a result, glaciers in these valleys remained active and retreated up valley. The pattern of glaciation in the Cascade Mountains was similar to that of other areas which underwent mixed mountain and ice sheet glaciation, such as the Presidential Range in New Hampshire, the Green Mountains in Vermont, mountain ranges in west central Maine and the Insular Mountains on Vancouver Island. However, deglaciation in al l areas was complex and depended strongly on local conditions. For this reason local patterns cannot be predicted easily on the basis of glaciation style. The value of an understanding of glaciation style to improve the accuracy of terrain mapping was also investigated. It was found that the model developed for the Cascade Mountains was of some use in predicting the presence of fine-textured material in valley bottoms and for the prediction of glaciofluvial material overlying till . However fine-textured sediments were not found in al l valleys which were predicted to contain them. The model appears to be most useful as an indicator of where to concentrate field checking in order to locate fine-textured sediments.

The purpose of this thesis is to describe in detail the fonn, lithology, elevation, tflt and distribution of abandoned glacial lake shoreline features and associated fluvioglacial and glacial deposits of Southwest Labrador Qnap 1). These characteristics are the result of distinct geomorphic and geophysical processes operating in late glacial and post glacial times and therefore a study of these characteristics reveals certain facts about the glacierization of Labrador-Ungava* and the deglaci erization of Southwest Labrador. The tilt of the glacial lake shoreline features is a result of glacial isostatic recovery and therefore the tilt of the shorelines reflects the differentiai thickness of the laurentide lee Sheet over Southwest Labrador during a certain stage in the Wisconsin period. If tilts of shorelines in other areas are used in conjunction with the tilts from Southwest Labrador it is possible to locate a point which represents a centre of ice dispersal of the Laurentide lee Sheet during a certain stage in the Wisconsin period.

During the last main phase of glaciations (26-13kaBP) an ice cap developed in south west Ireland and ice, from a dispersal centre in the vicinity of Kenmare, flowed north and diverged on the southern slopes of the Macgillycuddy’s Reeks. On these slopes, a weathering limit separates ice-moulded bedrock, on low ground, from frost-weathered terrain above. Assessment of bedrock dilation joint characteristics, Schmidt hammer R-value data, clay-sized mineral contents and magnetic properties of basal soil samples confirms significant contrasts in the degree of weathering above and below this limit. The weathering limit declines in altitude along former ice flow-lines and is confluent with morainic deposits on the eastern side of the Gap of Dunloe and on the western slopes of Skregbeg. This evidence supports the assertion that the high-level weathering limit is a periglacial trimline that marks the former maximum upper limit of the body of ice, which occupied this area of southwest Ireland during the LGM. This evidence, however, does not confute the notion that cold based, non-erosive plateau ice may have covered some or all of the upland surfaces that occur above the recorded weathering limits. Reconstruction of the former ice surface profile from periglacial trimline limits along three former flow lines yielded mean estimates for basal shear stress that ranged from 104.2 to 125.9 kPa. Although these values are high, they are within the range deemed normal for glaciers and ice sheets. The values suggest that the reconstructed areas of the ice cap were warm based and flowing on a bedrock substrate. This is supported by the geomorphological evidence of these areas, which shows that a landform – sediment association has developed consisting of zones of glacial scour and a thin, discontinuous drift cover. This contrasts with the glacial geomorphology of northern parts of the study area, where drift cover is largely continuous, and extensive in valley bottoms and on surrounding hillsides, and is associated with large lateral moraines.

This study investigates the sedimenology and geochemistry of Permian glacial sediments cropping out in the Bacchus Marsh and Derrinal areas in central Victoria and in the subsurface beneath the Cainozoic Murray Basin in Victoria, New South Wales and South Australia. Facies analysis of the Bacchus Marsh Formation, based on a critical review of literature on glacial sedimentary processes and environments, identifies the following major facies groups: 1. Subglacial tillites deposited beneath wet-based ice. Some of these tillites exhibit structures indicative of a number of subglacial processes such as frictional lodgement of large clasts, subglacial bed deformation, subglacial meltwater flow and subglacial size sorting of clasts. Other subglacial tillites are essentially structureless. 2. Bedded diamictites to sandstones deposited predominantly by ice-rafting of debris into standing water. 3. Fluvial outwash sandstone and conglomorate facies that are finer-grained than typical proglacial outwash facies. 4. Deltas and subaqueous outwash fans vary from sandy sediments deposited by proglacial and subglacial streams to coarse, poorly sorted complexes deposited as debris aprons close to the ice front. Abundant underflow deposits suggest that less than normal marine salinities prevailed in these water bodies, even if they were arms of the sea. 5. Supraglacial tillites consisting of sandy diamictites to pebble conglomerates.

Thesis (Ph. D.)--Texas State University-San Marcos, 2007. / Vita. Appendices: leaves 178-213. Includes bibliographical references (leaves 214-234).

Thesis (M. Sc.)--University of Canterbury, 2008. / Typescript (photocopy). One map in pocket. Includes bibliographical references (leaves 131-145). Also available via the World Wide Web.

Thesis (M.Sc.)--Memorial University of Newfoundland. / Typescript. Bibliography : leaves 117-121. Also available online.