Cryoconite as an efficient monitor for the deposition of radioactive fallout in glacial environments

Abstract

Abstract. Cryoconite is extremely rich in natural and artificial radionuclides, but a comprehensive discussion about its ability to accumulate radioactivity is lacking. A characterization of cryoconite from two Alpine glaciers is presented and discussed. Results confirm that cryoconite is among the most radioactive environmental matrices, with activity concentrations exceeding 10,000 Bq kg−1 for single radionuclides. Atomic and activity ratios of Pu and Cs radioactive isotopes reveal that the artificial radioactivity of Alpine cryoconite is mostly related to the stratospheric fallout from nuclear weapon tests and to the 1986 Chernobyl accidents. The signature of cryoconite radioactivity is thus influenced by both local and more widespread events. The extreme accumulation of radioactivity in cryoconite can be explained only considering the glacial environment as a whole, and particularly the interaction between ice, meltwater, cryoconite and atmospheric deposition. Cryoconite is an ideal monitor to investigate the deposition and occurrence of natural and artificial radioactive species in glacial environment.

Radioecological and geochemical peculiarities of cryoconite on Novaya Zemlya glaciers

“…Cryoconite holes on a glacier surface may survive for years 42 , accumulating precipitated matter, radionuclides of various origins in particular, which are transported into cryoconite via meltwater. For example, high concentrations of 210 Pb (T 1/2 = 22.2 years) and 7 Be (T 1/2 = 53.2 days) have been reported in cryoconite 1 , 2 , 8 – 12 , 14 . 210 Pb results from Rn decay, which, in turn, is produced from Ra present in rocks and soils in trace amounts.…”

Diel transcriptional pattern contributes to functional and taxonomic diversity in supraglacial microbial communities

“…Telling and colleagues reported that sufficient H 2 is produced to support methanogenesis under a Greenland glacier (Telling et al , 2015). Moreover, recent studies demonstrated that cryoconite is among the most radioactive environmental matrices, with activity concentrations exceeding 10,000 Bq kg-1 for single radionuclides (Łokas et al , 2016; Baccolo et al , 2019). This radioactivity might cause radiolytic H 2 production in the cryoconite holes, which, in turn, supports bacterial metabolism as already reported in deep subsurface environments (Lin et al , 2005).…”