Application of Environmental Tracers in the Analysis of Flow in Discontinuous Permafrost Aquifers
We present two studies focused on floodplain and sub-lake taliks in Interior Alaska that use chemical and physical tracers to characterize seasonal groundwater flow dynamics of supra- and sub-permafrost groundwater in discontinuous permafrost aquifers. Results from our study of the Tanana River floodplain near Fairbanks show that stable water isotopes, deuterium (δ2H) and oxygen-18 (δ18O), can be used to distinguish supra- and sub-permafrost groundwater. At a different study site consisting of two lakes with varying degrees of talik formation in the Goldstream Creek Basin near Fairbanks we combine the analysis of major cations and anions, alkalinity, basic field parameters, and stable water isotopes to distinguish sources of water and contributions to the lakes. Both studies demonstrate the complexity and seasonal variability of flow dynamics in open taliks as well as provide several conceptual models for the flow of groundwater within open taliks that can be used as a baseline for groundwater models in discontinuous permafrost regions.