Observations and modeling of slushflows from Atigun Pass, Alaska

Slushflows consist of a mixture of snow, water, and ice and often entrain debris or sediments. The high mobility and high density of the flows make them a considerable natural hazard, endangering settlements and infrastructure. They are most commonly associated with higher latitudes, such as Norway, Iceland, or Alaska, but have also been reported in various other countries, including regions such as the Alps. This paper describes slushflows near Atigun Pass, Alaska, which were well documented in a study for the Alyeska Pipeline Service Company (APSC) in 1982. The information has been privately held and is now being released for research purposes. Moreover, state-of-the-art modeling techniques are introduced and applied to the described slushflows, considering both depth-averaged and depth-resolved (three-dimensional) numerical methods with viscoplastic and elasto-viscoplastic rheological models. The observations and modeling approaches presented in this study provide insights that can improve the understanding and assessment of slushflows and their dynamics.