Slush-Ice Berm Formation on the West Coast of Alaska

• Published in: ARCTIC
• Main Authors: Eerkes-Medrano, Laura, Atkinson, David E., Eicken, Hajo, Nayokpuk, Bill, Sookiayak, Harvey, Engott, Eddie, Weyapuk, Winton Jr
• Format: Article in Journal/Newspaper
• Language: English
• Published: Arctic 2017
• Subjects: slush-ice berm; community observations; local knowledge; synoptic; weather; coastal; Alaska; sea ice; Arctic; Atkinson; Fairbanks; Sea ice
• Online Access: https://doi.org/10.14430/arctic4644; https://dspace.library.uvic.ca//handle/1828/9941

Some coastal communities in western Alaska have observed the occurrence of "slush-ice berms." These features typically form during freeze-up, when ice crystal-laden water accumulates in piles on the shore. Slush-ice berms can protect towns from storm surge, and they can limit access to the water. Local observations from the communities of Gambell, Shaktoolik, Shishmaref, and Wales were synthesized to develop a taxonomy of slush-ice berm types and a conceptual process model that describes how they form and decay. Results indicated two types of slush-ice berm formation processes: in situ (forming in place) and advective (pushed in by storm winds). Several formation mechanisms were noted for the crystals that compose in situ berms. Cold air temperatures cool the surface of the water, and winds that translate surface cooling through a greater depth aid crystal formation. Snow landing in the water cools via melting of the snow and by contributing crystals directly to the water. A negative surge can expose the wet beach to cold air, allowing crystals to form on the beach, which are then picked up by waves. Slush crystals for advective berm events form offshore. Winds move the slush towards shore, where it accumulates, and wind-induced waves move it up onto the beach. The authors are grateful to the residents of Gambell, Shaktoolik, and Shishmaref who welcomed us in their villages and homes, and to the Tribal Councils for their support to do this work. David Atkinson of the Department of Geography, University of Victoria, in collaboration with Hajo Eicken and Craig Gerlach, University of Alaska Fairbanks, received funding from the Western Alaska Landscape Conservation Cooperative and the National Oceanic and Atmospheric Administration to conduct a study based on work with community observers, develop a conceptual model of slush-ice berm formation, and identify the impacts of storms and adverse weather on community activities and infrastructure. Funding support from the National Science Foundation for the SIZONet ...