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In September 2008, freshening of near-bottom water and an increase in concentration of suspended particles were observed in the western part of southern Lake Baikal. The reduction in the content of total dissolved solids was about 0.4-0.7 mg/kg (0.7 %), and average suspended particle concentration increased strongly to 6-9 mg/l, the background value being 0.2 mg/l. The spatial distribution of these waters was virtually identical to the focal area of the M6.2 Kultuk earthquake that occurred on 27 August 2008. It is suggested that there was a causal relationship between these two phenomena. Freshening of a significant amount (about 20 km) of near-bottom waters was plausibly caused by an input of poorly mineralized pore waters from bottom sediments as a result of dissociation of methane gas hydrates suspected to occur in the area. The energy radiated by the earthquake source was four orders of magnitude smaller than that needed to explain the observed freshening of near-bottom waters. This points to other mechanisms leading to seismic-induced sediment failure and possible subsequent hydrate dissociation in the case of the Kultuk earthquake. [ABSTRACT FROM AUTHOR]

Abstract: We study the OI 630 and 557.7nm nightglow disturbances during geomagnetic storms using mathematical simulation, GPS total electron content measurements and optical observations in Eastern Siberia (52°N, 103°E). Revealed were several tens of geomagnetic storms when the 557.7 and 630nm emission disturbances сlose-in-amplitude observed during night. These disturbances were similar in shape and synchronous. The 557.7 and 630nm emission variations correlated with the total electron content disturbances. We suggested that the 557.7nm emission disturbances may result from the O2 + dissociative recombination reaction in this case and they are caused by variations in the parameters of the ionospheric F-layer. It was obtained that the ratio of the green and red volume emission intensities in the F region may vary during magnetic storms. This ratio (V 557.7/V 630) can be modified because of the F region components disturbances. [Copyright &y& Elsevier]

The article assesses the modern reserves of hydrates in the bottom sediments of Lake Baikal in Russia, its stability and emissions of methane during dissociation of methane hydrates resulting from global warming. The authors conducted numerical experiments using the method of for calculation of methane reserves in the bottom deposits of gas hydrates similarly to measure the time intervals required for the dissociation of hydrates. They calculated the thickness of hydrate stability zone (HSZ) for a period of 15000 years at temperature increased by 1 degree Celsius and 3 degrees Celsius relative to the modern bottom temperature as the upper boundary condition.