Quantification of Arctic soil and permafrost properties using ground penetrating radar

Abstract

Improving understanding of Arctic ecosystem functioning and parameterization of models that simulate freeze-thaw dynamics require advances in quantifying soil and snow properties. Due to the significant spatiotemporal variability of soil properties and the limited information provided by point-scale measurements (e.g., cores), geophysical methods hold potential for improving soil and permafrost characterization. In this study, we evaluate the use of Ground Penetrating Radar (GPR) to estimate thaw layer thickness, snow depth and ice-wedge characteristics in polygonal-shaped tundra in Barrow, AK. To this end, we analyze GPR and point-scale measurements collected along several parallel transects at the end of the growing season and the end of winter. A synthetic study is also performed to understand the GPR signal response to ice-wedge characteristics. Results show that GPR data collected during the growing season provide reliable estimates of thaw depth although strong spatial heterogeneity in soil properties can impair the estimates. While previous studies have documented the value of GPR for providing thaw depth estimates during the growing season, results from this study suggest that GPR methods are also useful for estimating active layer thickness during the frozen season, snow thickness and geometry of permafrost features, such as ice-wedges.