Model of formation of double structure gas hydrates in Lake Baikal based on isotopic data
Hachikubo, A.; Khlystov, O.; Manakov, A.; Kida, M.; Krylov, A.; Sakagami, H.; Minami, H.; Takahashi, N.; Shoji, H.; Kalmychkov, G.; Poort, J. (2009). Model of formation of double structure gas hydrates in Lake Baikal based on isotopic data. Geophys. Res. Lett. 36(L18504): 5. dx.doi.org/10.1029/2009GL039805
In: Geophysical Research Letters. American Geophysical Union: Washington. ISSN 0094-8276; e-ISSN 1944-8007, more
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| Author keywords |
gas hydrate; Lake Baikal; stable isotope |
| Authors | | Top |
- Hachikubo, A.
- Khlystov, O.
- Manakov, A.
- Kida, M.
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- Krylov, A.
- Sakagami, H.
- Minami, H.
- Takahashi, N.
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- Shoji, H.
- Kalmychkov, G.
- Poort, J., more
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| Abstract |
We measured the isotopic compositions of methane (C1) and ethane (C2) of hydrate-bound gas and of dissolved gas in pore water retrieved from bottom sediments in Lake Baikal. Both structure I (sI:3%C2) and II (sII:14%C2) gas hydrates are observed in the same sediment cores in Kukuy K-2 mud volcano. We found that C2 dD of sI gas hydrate is larger than that of sII, whereas C1 d13C, C1 dD and C2 d13C values are practically the same in both hydrate structures. d13C of C1 and C2 of hydrate-bound gas are several permil smaller than those in pore water, showing that the current pore water is not the source of gas hydrates. These findings lead to a new model where the sII gas hydrates were formed prior to the sI hydrates. |
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