Geophysical imaging of permafrost conditions along the northern Yukon Alaska Highway

Three sections of the northern Yukon Alaska Highway have been identified for testing the usefulness of geophysical surveys for understanding permafrost degradation and assisting with highway management. Results from capacitive resistivity and ground-penetrating radar surveys are analysed and interpreted along with surficial maps, geotechnical borehole records, and surface observations of highway roughness and distress. Observed damage appears to be associated with a variety of ground ice conditions. The geophysical results help elucidate the terrain conditions and support the conclusion that multiple subsurface processes contribute to highway degradation. Several geophysical signatures are interpreted as indicative of terrain conditions involving ice-rich ground, frozen ground, thaw-susceptible sediments and shallow groundwater.