1. Methane in gas shows from boreholes in epigenetic permafrost of Siberian arctic
- Author
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Alexander Kholodov, Elizaveta Rivkina, Gleb Kraev, Tatiana A. Vishnivetskaya, Andrei Belonosov, Kanayim Teshebaeva, Dmitrii Zamolodchikov, Jacobus van Huissteden, Alexander Smirnov, Anton Kudryavtsev, and Earth and Climate
- Subjects
Fluxes of CH ,Methane accumulations ,010504 meteorology & atmospheric sciences ,Clathrate hydrate ,Borehole ,Geochemistry ,010502 geochemistry & geophysics ,Permafrost ,01 natural sciences ,Methane ,fluxes of CH4 ,Cryogenic transport ,Atmosphere ,chemistry.chemical_compound ,SDG 13 - Climate Action ,0105 earth and related environmental sciences ,Global warming ,lcsh:QE1-996.5 ,Terrestrial seeps ,lcsh:Geology ,Tectonics ,Methane-hydrates ,Arctic ,chemistry ,Epigenetic cryogenesis ,Permeability of permafrost ,General Earth and Planetary Sciences ,Environmental science ,Pingo drilling - Abstract
The gas shows in the permafrost zone represent a hazard for exploration, form the surface features, and are improperly estimated in the global methane budget. They contain methane of either surficial or deep-Earth origin accumulated earlier in the form of gas or gas hydrates in lithological traps in permafrost. From these traps, it rises through conduits, which have tectonic origin or are associated with permafrost degradation. We report methane fluxes from 20-m to 30-m deep boreholes, which are the artificial conduits for gas from permafrost in Siberia. The dynamics of degassing the traps was studied using static chambers, and compared to the concentration of methane in permafrost as analyzed by the headspace method and gas chromatography. More than 53 g of CH4 could be released to the atmosphere at rates exceeding 9 g of CH4 m&minus, 2 s&minus, 1 from a trap in epigenetic permafrost disconnected from traditional geological sources over a period from a few hours to several days. The amount of methane released from a borehole exceeded the amount of the gas that was enclosed in large volumes of permafrost within a diameter up to 5 meters around the borehole. Such gas shows could be by mistake assumed as permanent gas seeps, which leads to the overestimation of the role of permafrost in global warming.
- Published
- 2019
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