| Abstract/Description or Keywords |
This thesis is a five-chapter investigation of glacier change in the Cariboo Mountains of British Columbia. In chapter one I discuss the importance of glaciers, introduce the glaciers of the Cariboo Mountains, and outline the objectives and structure of this thesis. In chapter two I compare three methods to estimate annual glacier mass balance of a 9.5 km2 mountain glacier for years 2009, 2010, and 2011. I find two geodetic methods, real-time kinematic GPS (global positioning system) and photogrammetry, to provide a valuable measure of glacier-wide annual mass balance that is complementary to the glaciological method. In chapter three I reconstruct the terminus position of the same mountain glacier for the period 1959-2007 from a series of annual push moraines. Annual recession of this glacier, the longest record for a North American glacier, is controlled by air temperature during the ablation season and accumulation season precipitation during the previous decade. I demonstrate an immediate glacier terminus reaction to summer and annual mass balance and a delayed reaction to winter and annual balance. In chapter four I calculate dimensional change for 33 representative glaciers in the Cariboo Mountains for the latter half of the twentieth century. I show the period 1952- 1985, when nine glaciers advanced, to be one of little net change for Cariboo Mountains glaciers. After 1985, however, rates of recession and thinning increased substantially. Comparison with climatological records reveals this marked change is due to both increased ablation season temperature and decreased accumulation season precipitation. I show glacier response to climate over this period to be highly variable and that relations between response and glacier morphometry are not consistent temporally. In chapter five I conclude this thesis with the progress gained through my research, study limitations, and the knowledge gaps that remain. Finally, I make 10 recommendations that will address knowledge gaps, and improve understanding of glacier change. |
