Assessment of radioactivity of cryoconites from glaciers of Elbrus mountain and glacial soils of Elbrus region, Russia

The paper presents data on radionuclide activity in cryoconites of Elbrus Mountain glaciers and periglacial soils. The study was conducted on the glaciers of the Elbrus Mountain—Maly Azau, Garabashi, Terskol and in the area of Prielbrusye, Kabardino-Balkarian Republic, Russia. Specific activity of natural radionuclides (K-40, U-235, U-238, Th-232) and cosmogenic Be-7 and technogenically orginated Cs-137 was determined. It was shown that activity of all investigated natural radionuclides in the samples taken on the studied glaciers is higher on Maly Azau, and cosmogenic Be-7 and technogenic Cs-137 at Garabashi. Revealed that cryoconites in the Arctic and Transcaucasia comparable to our data, and the Alpine glaciers have a higher specific activity natural radionuclides. The activity of cosmogenic radionuclide Be-7 in cryoconites of Elbrus glaciers was below the world average and amounted to 12.7–60 Bq/kg. In contrast to cryoconites from glaciers of other regions of the Earth, where very high concentrations of Cs-137 were found, in samples of cryoconites from glaciers studied by us this radionuclide showed relatively low values 0.44–68.2 Bq/kg. The data obtained in the study supplement the information on the geographical features of radioactive contamination of cryoconites of glaciers and periglacial soils mountainous areas.