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 CH 4 could be released to the atmosphere at rates exceeding 9 g of CH 4 m −2 s −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.
Original language | English |
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Article number | 67 |
Pages (from-to) | 1-17 |
Number of pages | 17 |
Journal | Geosciences (Switzerland) |
Volume | 9 |
Issue number | 2 |
Early online date | 29 Jan 2019 |
DOIs | |
Publication status | Published - Feb 2019 |
Funding
This research was funded by the Russian Academy of Sciences: grant numbers AAAA-A18-118013190182-3, AAAA-A18-118013190181-6, Russian Foundation for Basic Research 18-05-60279-Arktika, the National Science Foundation DEB-1442262, and the Nederlandse Organisatie voor Wetenschappelijk Onderzoek grant number ALW-GO/16-13.
Funders | Funder number |
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National Science Foundation | DEB-1442262, 1442262 |
Russian Foundation for Basic Research | 18-05-60279 |
Russian Academy of Sciences | AAAA-A18-118013190182-3, AAAA-A18-118013190181-6 |
Keywords
- Cryogenic transport
- Epigenetic cryogenesis
- Fluxes of CH
- Methane accumulations
- Methane-hydrates
- Permeability of permafrost
- Pingo drilling
- Terrestrial seeps