Characterization of active layer at different degrees of patterned ground development using electrical resistivity tomography survey

Active layer thickness in extremely cold regions is an indicator of global climate change, but it is also affected by the terrain types. Among the different terrain types typical to cold regions, patterned ground is of interest because it develops over time. Thus, investigating the active layer at different degrees of patterned ground development is required to understand the variability in its distribution. In this study, an electrical resistivity tomography (ERT) survey is conducted at three study sites to investigate the distribution of the active layer according to the degree of patterned ground development. The results of the ERT surveys show that the active layer is thinner, and the patterned ground develops better on an active layer with a small slope and stagnant porewater. Thawing of permafrost may be accelerated around patterned ground. As the ERT survey investigates geological structures without disturbing the target ground, it may be an effective method to monitor geological structures in extremely cold regions and interactions of the active layer with the surrounding conditions. •ERT surveys are conducted in study areas at different degree of PPG development.•Degree of PPG development is affected by the slope and thickness of active layer.•PPG commonly develops on the surface above the syncline-shaped interface•Thawing of the permafrost is accelerated around the patterned ground.