Speaker: Dr. Gwenn Flowers; Professor of Earth Sciences at Simon Fraser University
Glaciers of the St. Elias Mountains, straddling the Alaska-Yukon-British Columbia border, form the largest contiguous icefield outside of the polar regions with ~30,000 km2 of ice cover. These glaciers have been thinning at a rate of about 0.5 m per year over the last 50 years, and are now making globally significant contributions to sea level. The St. Elias Mountains also harbor a high concentration of surging and tidewater glaciers, whose internal dynamics have the potential to confound the climate signal. With the aim of unraveling some of the internal and external drivers of glacier change, we explore the thermal and flow regimes of land-terminating valley glaciers on the northern side of the range, including the environmental and geological controls on glacier surging. We also examine the dynamics of unstable lakes that form as glacier tributaries detach. Using geophysical and geotechnical field measurements, combined with statistical analysis and numerical modeling, we are beginning to disentangle the contributions of the geologic substrate, the environmental setting, internal ice dynamics and climate change to observed glacier behavior in this ice-rich part of the world.