Reconnaissance GPR survey of the ice caps on islands of Wilhelm Archipelago and on Berthelot island (West Antarctica)

Abstract

In this paper results of Antarctic ice caps investigations with GPR are represented. Local glaciological investigations of small glaciers on islands at the western coast of the AP are rare. Ice thickness is an important parameter for ice mass balance calculation. Investigation of the layering and in-situ sampling help to reveal information about past climate conditions and to understand glacio-geological history of the region. However, modern database Global Terrestrial Network for Glaciers contains neither the information about the thickness nor about interior structure of the ice caps discussed in this paper. The research is aimed at investigating the thickness and interior structure of the ice caps on Antarctic islands Plйneau, Petermann, Booth, Berthelot and Dannebrog. This territory was described only on the level of pioneering research in 19—20th centuries. The aim of the research is to obtain data about the general structure of the ice caps and ice thickness. Ground penetrating radar (GPR) VIY 3-300 (300 MHz) was applied to the surveying. Processed GPR profiles show up to 14 layers (Plйneau) inside the ice caps. There are interior crevasses, zones of moisture concentration and voids. Maps of the ice thickness were built for each island. The ice thickness on Dannebrog, Booth and part of Plйneau islands is more than 27 m, so it is recommended to use less frequency of the antennae than 300 MHz for a deeper and more detailed research of these ice caps. There are crevasses inside the ice near the surface, so for further investigations it is better to use special equipment to prevent any emergency situations (ropes, crampons, ice-hammerd, etc.). Landing sites on the islands with better access to the territories are mentioned in this paper.