Sublacustrine mud volcanoes and methane seeps caused by dissociation of gas hydrates in Lake Baikal
Van Rensbergen, P.; De Batist, M.; Klerkx, J. ; Hus, R.; Poort, J.; Vanneste, M.; Granin, N.; Khlystov, O.; Krinitsky, P. (2002). Sublacustrine mud volcanoes and methane seeps caused by dissociation of gas hydrates in Lake Baikal. Geology (Boulder Colo.) 30(7): 631-634. dx.doi.org/10.1130/0091-7613(2002)030<0631:SMVAMS>2.0.CO;2 In: Geology. Geological Society of America: Boulder. ISSN 0091-7613; e-ISSN 1943-2682, more |  |
| Author keywords | gas hydrates; hydrothermal vents; Lake Baikal; methane; mud volcanoes; seepage |
| Authors | | Top | - Van Rensbergen, P., more
- De Batist, M., more
- Klerkx, J.
| - Hus, R.
- Poort, J., more
- Vanneste, M., more
| - Granin, N.
- Khlystov, O.
- Krinitsky, P.
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| Abstract | Four lake-floor seeps have been studied in the gas-hydrate area in Lake Baikal's South Basin by using side-scan sonar, detailed bathymetry, measurements of near-bottom water properties, heat-flow measurements, and selected seismic profiles in relation to results from geochemical pore-water analysis. The seeps at the lake floor are identified as methane seeps and occur in an area of high heat flow, where the base of the gas-hydrate layer shallows rapidly toward the vent sites from 400 m to 150 m below the lake floor. At the site of the seep, a vertical fluid conduit disrupts the sedimentary stratification from the base of the hydrate layer to the lake floor. The seeps are interpreted to result from local destabilization of gas-hydrate caused by a pulse of hydrothermal fluid flow along an active fault segment. This is the first time that methane seeps and/or mud volcanoes associated with gas-hydrate destabilization have been observed in a sublacustrine setting. The finding demonstrates the potential of tectonically controlled gas-hydrate destabilization to cause extreme pore-fluid overpressure and short-lived mud volcanism. |
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