Anticipating rates of deglaciation in Alaska: Controls on the mass loss and morphology of the debris covered terminus of Kennicott Glacier, Wrangell - St. Elias National Park

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Landscapes in glacial environments change rapidly due to shrinking glaciers. Many glaciers in Alaska are covered by a layer of rocks and sediment, but there are very few direct measurements of how these debris-covered glaciers decay and affect glacier decline. The debris cover is expected to suppress glacier melting, but studies in the Himalayas have shown that many heavily debris-covered glacier tongues thin and decay just as fast as similar debris-free glaciers. The underlying mechanisms for this more rapid than expected glacier change are not well understood. Very limited observations exist in Alaska, where many glaciers are heavily debris-covered. A better understanding of these glaciers is necessary to develop better models predicting how they will melt and affect landscapes in the future.The overall goal of this project is to investigate the role of debris cover in modulating glacier surface and glacier mass change on the declining Kennicott Glacier in Alaska. The researchers will characterize the debris cover and observe the pattern and rate of dynamic change of the debris-covered lower reaches of Kennicott Glacier using field observations and remote sensing, to quantify the effect of debris cover on the annual mass change of the entire glacier. They will collect field data including meteorological and mass balance observations to constrain modeling on both detailed and larger spatial scales. The goal is to develop a model that can parameterize both melt suppression under thick debris and melt enhancement across ice cliffs, making it suitable for application on a regional scale. The project will provide training for several students, and field study examples for an international class of glaciology graduate students attending a successful summer school at this site. It also allows the work to be used by several local educational programs outside glaciology. What is learned about changing glaciers at this site will be available to visitors of Wrangell-Saint Elias National Park.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.