Unusual interactions between seawater, undersea permafrost, and deposits of ‘frozen’ methane lead to the accelerated release of natural gas into the atmosphere. Such was the conclusion of Russian scientists who published their study outcomes in Geosciences. The study is co-authored by the specialists from Skoltech, Tomsk Polytechnic University, and the V. I. Il'ichev Pacific Oceanological Institute of FEB RAS.
The researchers conducted experiments on the interaction of frozen rocks containing relict methane hydrates, with salt solutions at various negative temperatures and found that salt migration to frozen hydrate-containing rocks activates the decomposition of pore gas hydrates and accelerates their thawing.
One of the largest sources of methane emissions into the atmosphere in the Arctic is the East Siberian Shelf. Most of methane enters the atmosphere during the decomposition of gas hydrates that are crystalline compounds formed from gas and water at low temperatures and high pressure and resembling an ice mass that is hardtop call gas in the solid state. The volume of the compound is 160-180 times higher than the one occupied by pure gas. When the conditions of their stable existence change, gas hydrates formed in favorable natural conditions many thousands of years ago can begin to decompose into gas and water.
According to the researchers, since these processes increase methane emissions from frozen hydrate-containing rocks, which is important to understand the mechanism of a massive release of methane from bottom sediments, the results of experiments were used to create a model of the interaction of the hydrate-saturated strata with sea water on the Arctic shelf. The scientists are confident that the data obtained allow them to explain the cause of the upward movement of the methane front discovered by the authors at the East Siberian Arctic Shelf based on complex geophysical and biogeochemical studies.
Tomsk Polytechnic University is a platform for the implementation of the large scientific project The Siberian Arctic Shelf as a Source of Greenhouse Gases of Planetary Significance: Quantitative Assessment of Fluxes and Identification of Possible Environmental and Climate Consequences. The project was supported by the grants of the Government of the Russian Federation (project supervisor – TPU Prof Igor Semiletov) and the Russian Science Foundation (project supervisor – TPU Prof Natalia Shakhova). Over the first four years of the project implementation, the team published over 70 articles in the Q1 journals, their cumulative IF exceeds 200. The outcomes of these studies greatly contribute to the understanding of climate system functioning of the Arctic. One of the recent articles was published in Science Advances (IF 11.5).