A Review of the Utility of Remote Sensing in Alaskan Permafrost Studies

This paper reviews the uses of remote sensing techniques for studies of permafrost related features and processes in Alaska. Remote sensing is ideally suited for studying the Arctic because of the inherent problems associated with obtaining in situ measurements in the harsh Arctic environment. Aircraft thermal infrared imagery, aircraft SAR (Synthetic-Aperture Radar), and helicopter-borne shortpulse radar data are also discussed. It is shown that thermal infrared, aircraft SAR, and Landsat data are all useful for qualitative determination of lake depth of the thaw lakes in northern Alaska. Lakes frozen to their beds can be distinquished from lakes not frozen to their beds using thermal infrared and aircraft SAR imagery. Summer Landsat imagery has been used to monitor lake ice cover dissipation, a relative measure of ice thickness and lake depth. Landsat data have also been used to study the distribution and interannual variability of stream aufeis on the Arctic Slope of Alaska. In addition, break-up characteristics and floods have been studied using Landsat data. Shortpulse radar data are being used experimentally to study subsurface permafrost features, and to examine subsurface homogeneity for construction purposes. In addition, Landsat digital data have been used to measure the one year recovery of tundra following a wildfire in northwestern Alaska. Use of remotely sensed data has substantially increased our understanding of processes operating in Arctic land areas as evidenced by the variety of studies that have been undertaken using data from different parts of the electromagnetic spectrum.