Postglacial landscape change in western Canada

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My students and I are involved in understanding how the landscape in western Canada adjusted to the rapid demise of the ice sheets that covered it during the last ice age, and how the landscape has responded to subsequent changes in climate. Our principal research is done in the Cordilleran mountains of B.C. where sediment deposited in the mountains by the glaciers were left in very unstable positions, and much of it was rapidly eroded by streams and deposited in more stable positions near the valley bottoms. Many of these sediments can be seen today as occupying large fan-shaped landforms (alluvial and mudflow fans) that developed on high river terraces along valleys. These large landforms rest in fragile positions and are thus expected to be extremely sensitive to changes in climate. My research looks very carefully at when these fans started forming, and when they stopped forming; it also looks at their internal structure to find links between their mode of construction and changes in past climate. By understanding this we should be able to help predict the effect that future climate change will have on the stability of fragile landforms in British Columbia, and those in similar regions. Closely related to this study is research that I am conducting with colleagues at the Geological Survey of Canada and University of Lethbridge which involves landscape change on the Canadian prairies. In this case, we are studying large fields of sand dunes that are stable today, but become active during prolonged periods of hot and dry climate. As it is extremely rare to find organic matter for radiocarbon dating inside any of these landforms (fans or dunes), we rely on luminescence dating, which allows us to date when sediments buried within them were last exposed to sunlight. This method of dating, which is done in a special laboratory at University of the Fraser Valley, is inherently experimental, and laboratory procedures have to be modified and tested to suite each situation.