This study describes the pattern and extent of recent retreat using satellite imagery of an unnamed glacier in the Mamquam Range within Garibaldi Park and the Pacific Ranges of the Coast Mountains. The unnamed glacier has shown a unique pattern of retreat as it is a remnant of a once larger cirque glacier that separated from its upper accumulation zone through thinning and down-wasting in the late 20th century. The rate of glacial retreat was determined by comparing satellite images between 1985 and 2022. Comparisons of the images indicates that the glacier receded approximately 325 meters (13 m/y) and down-wasted at a rate of 14.5 m/y. We note newly exposed rock outcrops along all margins of the glacier. Inspection of Sentinel-2 multispectral imagery at the end of the mass balance year indicates that the accumulation area ratio (AAR) was far below the sustainable threshold of 0.3 in 2023. This glacier is projected to expose a concave rock basin, which will host a tarn due to the consistency of retreat. This pattern and rate glacial transformation will continue or accelerate if present climate projections are accurate, and the adjacent tarn provides a good model of the future of this unnamed glacier as it had succumbed to similar physical processes.
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