Thermokarst in Northern Alaska: Drivers of Where and When Permafrost Degrades
Andrew Balser, University of Alaska Fairbanks, on the variability of permafrost degradation in northwest Alaska.
Permafrost is defined simply: 'Ground remaining below 0 degrees C for two or more years consecutively'. However, in permafrost landscapes uniformity ends with the base definition. Surficial geology, vegetation, physiography and hydrology are among the highly variable landscape properties driving development of equally variable permafrost profiles, ground ice content and cryostructures. The where, when and how of permafrost degradation is equally variable, driven by the interplay of landscape properties, climate shifts, weather anomalies and fire. In northwest Alaska, specific weather events and seasonal shifts drive important thermokarst processes, suggesting the fate of permafrost carbon may depend heavily on how climate change influences seasonality, rather than on general climate warming alone.
Sponsored by the Dickey Center's Institute of Arctic Studies and the Center for Circumpolar Studies.