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The paper describes the algorithm and the results of the seismic hazard estimate in the Sakhalin and Southern Kurils region based on the data of the Japan Regional Catalogue (JMA). A nonlinear differential equation of the second order is used as a mathematical model, and algorithms for optimization and predictability estimation are presented by the author's solutions. The forecasting algorithm is based on the search for seismic activity zones in which the current activity trends correspond to foreshock sequences recorded before strong earthquakes (precedents) that have already occurred. The earthquake time is calculated with extrapolating the detected trends to the level of activity that occurred at the time of the precedent earthquake. By the example of precedent foreshock sequences in Japan, it is shown that the lead time of such a forecast reaches 10–15 years and its implementation is due to the preservation and stability of the identified trends. A map of potentially dangerous zones for Sakhalin and the Kuril Islands and some examples of calculating the time of strong earthquakes according to the JMA catalogue as of August 31, 2018 are presented. Action sequence in identifying the potentially dangerous trends in seismic activity and the specifics of possible use of the technique in the Sakhalin region are considered.

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Research subject and methods. The paper presents a review of available information on the atmosphere of Titan and its surface, necessary for the development of concepts of hydrocarbon formation, including the natural hydrocarbon synthesis, formation of prebiogenic states and origin of life. The presence of vast reserves of abiogenic hydrocarbons on Titan is extremely important for the theory of hydrocarbon genesis on the Earth, since any concept of naphthogenesis claiming to be a consistent explanation of the entire set of available facts must take into account the possibility of abiogenic formation of large accumulations of hydrocarbons.Results. It was shown that the hydrocarbon diversity of the atmosphere and surface of Titan is provided by the inflow of endogenous methane. Degassing processes on Titan are characterized by specific forms due to their flow through a liquid medium: 1) “gas-lifting degassing” forming numerous small depressions with increased fluid levels and, possibly, being the cause of “magic islands” in the sea of Ligeia; 2) limnological emissions of gaseous methane, followed by intensive cloud formation, the development of methane storms and large amounts of precipitation.Conclusions. It is concluded that the presence of active degassing processes on Titan in combination with the emerging models of its internal structure contribute to clarifying the previously proposed scheme of primary natural hydrocarbon synthesis in the depths of Titan.

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