Structure of the near-surface part of the glacier in the Thala Bay area (East Antarctica) based on 2018/2019 ground-penetrating radar survey

Abstract

The paper discusses the results of the ground-penetrating radar (GPR) survey carried out in February 2019 in the area of Thala Bay (Larsemann Hills, East Antarctica). Thala Bay is one of the strategic facilities of the Russian Antarctic Expedition (RAE) in the Progress station area as since 2019 heavy cargo has been unloaded here intended for the construction of new facilities at the Vostok station. Transportation of goods to the point of formation of logistic traverses takes place on ice tracks, whose safety must be evaluated taking into account the expanded system of crevasses. In addition, the current track is characterized by a significant slope of the terrain, which also complicates the relocation of heavy equipment.In February 2019, a GPR survey was carried out within the Thala Bay area to assess the possibility of organizing an alternative section of the route within it. According to the visual observations, this area was characterized by an extensive system of crevasses, the width of which at the surface reached 20-30 cm, and the prevailing longitudinal direction coincided with the direction of the route. The task of the geophysical survey was to map the crevasses not identified by visual inspection and to determine their morphology. According to the GPR data, it was shown that the crevasses within the site are located to the firn layer and are characterized by an irregular shape, significantly expanding at the deeper levels and reaching a width of 6 m. The results of the survey are illustrated with the scheme of the firn thickness which shows location of the crevasses. According to the recommendations of the authors, the section of the glacier is suitable for operation provided the glaciological situation using the GPR method is monitored annualy.