In recent years, cryoconite has received growing attention from a radioecological point of view, since several studies have shown that this material is extremely efficient in accumulating natural and anthropogenic radionuclides. The Novaya Zemlya Archipelago (Russian Arctic) hosts the second largest glacial system in the Arctic. From 1957 to 1962, numerous atmospheric nuclear explosions were conducted at Novaya Zemlya, but to date, very little is known about the radioecology of its ice cap. Analysis of radionuclides and other chemical elements in cryoconite holes on Nalli Glacier reveals the presence of two main zones at different altitudes that present different radiological features. The first zone is 130–210 m above sea level (a.s.l.), has low radioactivity, high concentrations of lithophile elements and a chalcophile content close to that of upper continental crust clarkes. The second zone (220–370 m a.s.l.) is characterized by high activity levels of radionuclides and “inversion” of geochemical behaviour with lower concentrations of lithophiles and higher chalcophiles. In the upper part of this zone (350–370 m a.s.l.), 137Cs activity reaches the record levels for Arctic cryoconite (5700–8100 Bq/kg). High levels of Sn, Sb, Bi and Ag, significantly exceeding those of upper continental crust clarkes, also appear here. We suggest that a buried layer of contaminated ice that formed during atmospheric nuclear tests serves as a local secondary source of radionuclide contamination. Its melting is responsible for the formation of this zone.
Due to climatic changes in Spitsbergen the glaciation of the Nordenskjold Land (West Spitsbergen) has significantly degraded over the past 100 years. Changes in glaciers are undoubtedly associated with intensive melting caused by a rise of summer air temperatures. Based on the results of field measurements of ablation on the East Grenford glacier, data on the ice reduction were obtained since 2004. Analysis of the results showed that magnitude of the surface ablation is in a good agreement with the values calculated by the Krenke–Hodakov formula, in which the argument is the average summer air temperature. The parabolic dependence of the Krenke-Hodakov formula with the exponent of 3.25 presented the best approximation to the field measurements for all high-altitude zones of the glacier with a correlation coefficient of 0.96. The calculated values of ablation of ice and snow were used to estimate the mass balance of the East Grenford glacier since 2004. The calculations were based on the following: measured values of jump in temperature at the boundary of the glacier, averaged values of the air temperature gradient, and averaged data on snow storage on the glacier. Data on the mass balance of the glacier is indicative of its shortening during the last decade, despite the interannual variations. In 2016, the glacier mass balance reached the lowest value equal to −1990 mm, the calculated value was equal to −1960 mm. Analysis of the data demonstrated that the average summer air temperature is the major factor affecting the glacier mass balance. These results may be useful for estimating melting and mass balance of a number of mountain glaciers of the Nordenskjold Land.
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