Identifying Ice Wedges in Ground Penetrating Radar data from the CRREL Permafrost Tunnel, Fox Alaska

Abstract

The warming of Alaska’s permafrost has been leading to thawing within its discontinuous permafrost. This can cause ice wedges to melt resulting in thermokarst formations such as sink holes and landslides which are causing damage to Alaskan infrastructure. To avoid developing further infrastructure in areas containing ice wedges, it is necessary to improve methods of detecting subsurface ground ice. Ground Penetrating Radar (GPR) is a nonintrusive remote sensing method of locating and characterizing permafrost and other subsurface features that are not evident on a cut face or surface. When applied to the detection of ice wedges at the CRREL (Cold Regions Research and Engineering Laboratory) permafrost tunnel in Fox, Alaska, a few identifying features were observed which corresponded with prior research. We first used GPR reflections of areas along the tunnel walls holding known ice wedges to verify the identifying features of an ice wedge within GPR data. We utilized these reflections as test data to identify possible ice wedges in locations where they were not observed on the tunnel walls.