No critical mercury emissions were detected in Svalbard during the melting of permafrost

The press service of the Russian Geographical Society showed the results of research conducted in the Arctic archipelago of Svalbard with the participation of Russian scientists. Specialists from the Arctic and Antarctic Research Institute, the Institute of Lake Science of the Russian Academy of Sciences, the Alfred Wegener Institute for Polar and Marine Research and the Technical University of Dresden have been studying the content of mercury and organic carbon in frozen quaternary sediments near the Russian village of Barentsburg for six years.

The scientists analyzed 157 samples from 15 wells, which made it possible to determine background concentrations in soils and marine sediments in the pre-industrial period and compare them with modern ones. There is an opinion that the thawing of frozen rocks against the background of climate change can lead to the entry of climatically and biologically active substances into the biosphere, for example, mercury.

However, studies conducted in Svalbard have shown that pre-industrial frozen marine sediments in the Barentsburg area contain more mercury than the modern bottom soils of most of the fjords of the archipelago. Mercury is also somewhat less in modern soils of Svalbard than in the studied frozen sediments aged 5-20 thousand years. This means that the concentration of mercury in the modern ecosystems of Svalbard fully fits into the natural norm that existed before man began to actively change the habitat.

Scientists are also skeptical about the theory that the degradation of permafrost can lead to a critical increase in the concentration of mercury in soils and bottom sediments. Studies have shown that mercury in frozen sediments, although more than in modern bottom sediments and soils, but this excess is not orders of magnitude, but the first tens of percent. At such concentrations, only a one-time release of mercury preserved in the permafrost can have a catastrophic impact on the biosphere. However, thawing of permafrost is a time—stretched process, which does not lead to the mobilization of the entire thawed thickness and the organic matter contained in it with mercury at once.