Ground-penetrating radar survey of subsurface features at the margin of ice sheet, East Antarctica

Abstract

The subglacial environment of East Antarctica remains largely unexplored. In this study, ground-penetrating radar (GPR) data of the ice-sheet margin in East Antarctica were collected and analysed, an average velocity of 0.18 m/ns was obtained through ice density conversion and common midpoint (CMP) survey. The thickness, internal layers, and bed elevation were used to determine the spatial characteristics of snow/firn in the survey area. The relative amplitudes of the reflections along the bedrock interface were computed to determine the potential presence of subglacial water in depressions, which is the most likely source of strong reflections at basal interfaces. Because the subglacial topography is associated with the dynamic characteristics of the ice sheet, the two-parameter roughness index was used to assess the regional roughness of the bedrock beneath the snow/firn and discuss the implications of changes at the bottom. This research provides insights into the physical characteristics of ice-sheet margins. The methodology proposed in this study should be applied in the future to quantify the physical parameters required for ice-sheet studies.