Tweedsmuir Glacier - an ACC Environment Grant preliminary report
Submitted by Dan Shugar — Associate Professor, Dept of Geoscience and Director, BSc Environmental Science Program at the University of Calgary: Water, Sediment, Hazards, and Earth-surface Dynamics (waterSHED) Lab
About the ACC Environment Grant
Every year the ACC awards a number of financial grants to help our community members get outside, follow their dreams and protect the environment. The ACC’s Environment Grant provides support for the protection and preservation of mountain and climbing environments, including the preservation of alpine flora and fauna in their natural habitat. Since 2002 the ACC has contributed over $75,000 to environmental projects. The deadline for applications for the ACC Environment Grant is January 31 annually.
About the Tweedsmuir Glacier project
Tweedsmuir Glacier is a very large (~65 km-long) glacier in the rugged St Elias Mountains in Tatshenshini-Alsek Provincial Park in northwest BC. It is what glaciologists call a “surge-type” glacier, which means its behaviour is characterized by intermittent episodes of fast flow and advance of the terminus, or snout, alternating with prolonged periods of quiescence when the glacier doesn’t move much, and spends its time melting in place.
Along the terminus of the glacier, Alsek River flows through a very narrow stretch of bedrock called Turnback Canyon, which is so turbulent and violent, that sockeye salmon cannot swim up it. In fact, whitewater rafters get a helicopter portage instead of running this section!
Previously-installed remote camera destroyed by bears.
Our team of glaciologists and geomorphologists is interested in understanding how the glacier has behaved in the recent geological past, and how it has influenced Alsek River and formation of Turnback Canyon.
Thanks to a grant awarded by The Alpine Club of Canada’s Environment Fund, we were able to visit Tweedsmuir Glacier in summer 2021 (postponed from 2020 due to COVID) to collect much-needed ice-penetrating radar data to determine the thickness of the glacier, and to retrieve some instruments we had deployed in 2019 (which were, unfortunately, destroyed by bears).
By dragging the radar across the ice (on skis in 2019, and on foot in 2021), we are hoping to gather enough data to build a 3D model of the terrain beneath the glacier, with the aim of forecasting what the future of the Tweedsmuir valley might look like as the glacier retreats.
The author and teammates Meghan Sharp and Dr Gwenn Flowers collecting ice-penetrating radar survey on Tweedsmuir Glacier.
Watch for more on this in an upcoming issue of the State of the Mountains Report.