ISSN 07479239, Seismic Instruments, 2015, Vol. 51, No. 2, pp. 176–189. © Allerton Press, Inc., 2015. Original Russian Text © V.N. Solovjev, I.N. Tikhonov, A.I. Kozhurin, 2014, published in Voprosy Inzhenernoi Seismologii, 2014, Vol. 41, No. 2, pp. 60–76. Refinement of Background Seismicity on the Survey Plot of Sakhalinskaya GRES2 (Sakhalin Island) V. N. Solovjeva, I. N. Tikhonova, and A. I. Kozhurinb, c a Institute of Marine Geology and Geophysics, Far Eastern Branch, Russian Academy of Sciences, ul. Nauki 1B, YuzhnoSakhalinsk, 693022 Russia b Institute of Volcanology and Seismology, Far Eastern Branch, Russian Academy of Sciences, br Piipa 9, PetropavlovskKamchatskii, 683006 Russia c Geological Institute, Russian Academy of Sciences, Pyzhevskii per. 7, Moscow, 119017 Russia emails:
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[email protected] Abstract—The background seismicity of the territory in the vicinity of the site of the planned construction of the Sakhalinskaya GRES2 power plant, in the region of the Poyasok Isthmus, is refined. The interpretation of aerial photos of the territory under study is performed including the survey plot. Five active faults, previ ously unknown, are discovered, four of which are identified with a high degree of reliability. All of them are located beyond the survey plot limits. Within the survey plot, no indications of active faults are found. Design response spectra are calculated for return periods of 500, 1000, and 5000 years, and accelerogram analogues are selected. Maps of detailed seismic zoning (DSZ) are developed in parameters of the macroseismic inten sity (IMSK) and the peak ground acceleration (PGA, g) with 5% damping for the return periods of 500, 1000, and 5000 years.