RADIOACTIVITY OF SURFACE MARINE SEDIMENTS OF THE CHAUN BAY. ANALYSIS OF NATURAL AND ANTHROPOGENIC ENVIRONMENTAL FACTORS

In: Ser-5_2023_4; Moscow University Bulletin Series 4 Geology, Heft №6_2023, S. 67-76

Abstract

The paper presents data on the spatial distribution of activity concentration of natural (232Th, 226Ra, 40K) and anthropogenic (137Cs) radionuclides in the surface layer of bottom sediments of the Chaun Bay of the East Siberian Sea. The measured activity of 232Th and 226Ra is typical for bottom sediments of the Arctic coastal zone and corresponds to the global level. The level of 137Cs activity in bottom sediments showed the absence of local sources of anthropogenic contamination in Chaun Bay, while the mean 40K activity concentration was 1.8 times higher than the global average. The results of statistical analysis showed that the dynamics of riverine run-off, thermoabrasion and currents, as well as aeolian and sea ice transport of sedimentary matter, are the main factors that determined the differences in the behaviour of the studied radionuclides in the surface bottom sediments of the Chaun Bay.