On the use of ground penetrating radar for detecting and reducing crevasse-hazard in Dronning Maud Land, Antarctica

Abstract

Abstract We present the results of ground penetrating radar (GPR) investigations performed during the Norwegian Antarctic Research Expedition 2005–2006 with the aim of detecting, mapping and mitigating crevasse hazard. The study focused primarily on a stretch of the route from the research station “Troll” to the cargo unloading area on the ice shelf margin, where the presence of crevasses has resulted in occasional material damage and constitutes a potential hazard to people safety. A 400-MHz GPR system was utilised to detect the crevasses and tentatively to enable a real-time assessment of the width of the cavities and of the thickness and structure of the snow bridges. An in situ validation of the information provided by different radar signatures was obtained by directly inspecting a number of crevasses. This also allowed us to mitigate the hazard by identifying weak areas and establishing safe crossing points. The interpretation of more ambiguous radar signatures is also validated by using a numerical model. Finally, we have tested the possibility of using radar antennas slanted in the drive direction to increase the detection distance as compared to the traditional down-looking installation. Our results confirm the reliability of GPR for the detection of crevasses and contribute to developing the radar into a standard tool for safer navigation in polar regions.