ИСТИНА

This study summarizes results from two expeditions- in 2011 and 2015- to King George Island (62˚ 25’S, 58˚ 53’W), part of the South Shetland Islands, 120 km off the west coast of Antarctica. The expedition aim was to better understand the link between cryosphere dynamics and changes in sediment redistribution. The assessment was based on the distribution of the fallout radionuclides 137Cs and 210Pbex, environmental radionuclides 40K, 226Ra, 238U and 232Th and landscape geochemical fingerprints, including sediment cores. In total 9 cores were taken (depth ranging between 0.8 and 1.26m) in 9 lakes located in the drainage basin related to the Bellingshausen Dome at the Fildes Peninsula and complementary at pro-glacial areas of the Admiralty Bay. These data were used to understand the ongoing erosion processes, calculate sedimentation rates, and identify possible sources of sediments. Further, high resolution digital surface models were made based on UAV surveys to assess the geomorphological processes taking place. These surveys took place in 2015 and 2017 and will be repeated in 2018. Local historical data from 1968 until 2009 showed that the Bellingshausen glacier lowered significantly, almost without boundaries changing. However, after 2009 until present, the glacier is showing an increase. The previous change in mass balance (Equilibrium-line altitude) could be correlated in this study positively correlated to a change in summer temperature (R2= 0.76) in this study, only a limited correlation was found with summer rains (R2=0.25).