The Information interdisciplinary database was used for construction of the deep structure model in the region of the Neftegorsk Earthquake which has occurred on 28 May 1995 in the North Sakhalin. The location of the earthquake epicentre was 52.60oN, 142.80oE with magnitude Ms=7.2. The hypocentre of Neftegorsk earthquake was found on a depth of 18 km. As a result of this disastrous earthquake a seismic rupture of north-northeast strike of an overall length of 35 km appeared which caused right-lateral strike-slip fault displacement with amplitude of the horizontal shift component up to 8 m and vertical upthrust component up to 2 m. The constructed model shows that North Sakhalin consists of the North Sakhalin sedimentary basin, the Deryugin basin and the ophiolite complex located between them. The Deryugin basin was formed on site of an ancient deep trench after subducting the Okhotsk sea plate under the volcanic arc along Sakhalin in the Late Cretaceous-Paleogene. The North Sakhalin sedimentary basin was formed on a place of back-arc basin at that time. The ophiolite complex combined by the ultrabasic rocks, fixes position of ancient subduction zone acting about 100ndash;60 million years ago. On a surface the subduction zone manifests itself as deep faults running along Sakhalin. The center of the Neftegorsk earthquake was directly formed by burst of activity of this ancient subduction zone. From a position of the ancient subduction zone under Sakhalin, which is a cause of strong earthquakes here, it follows that the region is one of seismic dangerous in Russia.
active continental margins, subduction zone, ophiolite complex, astenosphere diapir, earthquake
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