METHANE IN FROZEN AND THAWING SEDIMENTS OF WESTERN RUSSIAN ARCTIC
N.A. Zadorozhnaya1, G.E. Oblogov1,2, A.A. Vasiliev1,2, I.D. Streletskaya3, G.V. Malkova1,2, P.B. Semenov4, B.G. Vanshtein4
1Earth Cryosphere Institute, Tyumen Scientific Centre SB RAS, Malygina str. 86, Tyumen, 625026, Russia
2Tyumen State University, Volodarskogo str. 6, Tyumen, 625003, Russia
3Lomonosov Moscow State University, Leninskie Gory 1, Moscow, 119991, Russia
4All-Russia Scientific Research Institute of Geology and Mineral Resources of the World Ocean, Angliiskii prosp. 1, St. Petersburg, 190121, Russia
Keywords: methane, permafrost, transient layer, ground ice, methane emission, Marre-Sale, Pechora River mouth
Abstract
The results of studies of the methane content in the active layer and upper permafrost horizon in the areas of the Marre-Sale station (western Yamal Peninsula) and the Pechora River mouth are presented. Data on the methane content in Quaternary permafrost and ground ice of different geneses and data on methane emission from the surface of typical tundra in Marre-Sale are analyzed. The highest methane content in sediments of both the active layer and the upper permafrost is characteristic of boggy floodplains and waterlogged depressions on the surface of the marine terrace. In well-drained landscapes, methane is virtually absent in sediments of the active layer. In the upper permafrost, its content 5-6 times higher than in the overlying active layer. A large amount of methane (on average, about 2 mL/kg) is contained in loamy clay marine sediments at the base of the Marre-Sale section, as well as in the massive ice. The distribution of methane in permafrost and ground ice is close to a lognormal distribution. Significant methane flux (up to 10.7 mg/(m2 ·h ) has been determined for highly moistened surfaces occupying about 45-50 % of the area of a typical tundra.
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