Downstream impacts of glacial retreat in the Peyto Glacier basin, Banff National Park, Canada

Date
2025-01-29
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Abstract

Glacier retreat strongly influences the surrounding environment and downstream through landscape evolution, diurnal meltwater generation, sediment production, and sediment export. Proglacial environments, located in front of glaciers, are dynamic systems by continuous landscape processes seeking to reach a new equilibrium. An increasingly common feature in these environments is proglacial lakes, which act like dammed reservoirs, slowing water, and allowing for sediments to settle out of suspension. Peyto Basin has long been of interest to scholars and tourists; however, little research has focused on the development of Lake Munro, an ice-contact proglacial lake at the terminus of Peyto Glacier. To understand the implications of Lake Munro’s development, a multipronged approach was employed, examining lake area growth, glacier length changes, and downstream channel braiding. Additionally, ion contributions from waterbodies in the basin, sediment samples, and suspended sediment concentrations were analyzed and compared with available historic data. Our results show that Peyto Glacier has retreated 2048 +/- 5 m between 1952 and 2023, while Lake Munro expanded from non-existence to 0.305 +/- 0.010 km2 between 2008 and 2023, and is estimated to be trapping suspended sediments, with rough estimates suggest up to 60% of sediments being captured by Lake Munro. However, downstream proglacial channels rapidly replenish the larger grain sizes in the suspended sediment of Peyto Creek. Caldron Creek was identified as the highest contributor of ions to Peyto Creek, and downstream, Peyto Lake now exhibits a strong thermal stratification and has higher suspended sediment concentrations compared to historic data. Channel braiding is more variable in recent years, but further seasonal and intra-annual data should be analyzed before stronger relationships can be drawn. The findings highlight how glacial retreat, and the development of a proglacial lake impact downstream sediment concentrations, channel patterns, and grain size distribution in the Canadian Rockies. Continued research within the Peyto Basin will continue to highlight processes in the proglacial environment as Peyto Glacier retreats.

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Keywords
Mountains, Alberta, Proglacial Environment, Proglacial, Proglacial Hydrology, Suspended Sediment, Glacier, Climate Change, Peyto Lake, Peyto Glacier
Citation
Basiuk, H. (2025). Downstream impacts of glacial retreat in the Peyto Glacier basin, Banff National Park, Canada (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.