Permafrost archives of northern environmental change and permafrost landsystems of the Mackenzie valley

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The longterm impact of climate change on the permafrost landscape of northern Canada will be a defining issue in the 21st century. We have made little progress in decreasing our collective greenhouse gas emissions to the atmosphere, and the impacts of a warming climate are quickly exceeding nearly all of our terrestrial Quaternary analogues. For northern landscapes and communities, we must develop better tools to prepare for future thaw. Today, the most severely affected areas of the western Arctic are associated with buried glacier ice that has been relict for the last 10,000 years, but is now warming and becoming thaw susceptible at regional scales. This distribution of ground ice reflects the dynamics of glaciation and the burial of ice near the former ice margin in the Quaternary. Similarly, ground ice properties throughout northern Canada are a reflection of the recent geologic history and its interaction with past vegetation and climate. The interactions of these historical contingencies define regional permafrost landscape units, or Landsystems, that will define patterns of future response. Understanding other regional trajectories of thaw will depend on similar legacies of regional Quaternary geology that have strongly influenced the distribution and character of ground ice. Models exist at continental scales for future climate change impacts on permafrost, but the veracity of these models is limited by our understanding of the nature and distribution of ground ice, which in large part, will determine the susceptibility of areas to thaw. The objectives of this research are threefold: (1) to detail the landscape history of the Mackenzie valley, the impact of rapid deglaciation and resulting landforms during the late Pleistocene; (2) to establish these properties, regionally, through field mapping to provide a model for future thaw landscapes of the central and southern Mackenzie valley; and (3) develop and test new approaches to permafrost characterization using new tools such as CT scanning and gamma density that allow the non-destructive characterization of permafrost cores. This work requires multiple summers of fieldwork in the Mackenzie valley.