The present tectonics of Northeast Asia has been extensively investigated during the last 12 yr by using GPS techniques. Nevertheless, crustal velocity field of the southeast of Russia near the northeastern boundaries of the hypothesized Amurian microplate has not been defined yet. The GPS data collected between 1997 February and 2009 April at sites of the regional geodynamic network were used to estimate the recent geodynamic activity of this area. The calculated GPS velocities indicate almost internal (between network sites) and external (with respect to the Eurasian tectonic plate) stability of the investigated region. We have not found clear evidences of any notable present-day tectonic activity of the Central Sikhote-Alin Fault as a whole. This fault is the main tectonic unit that determines the geological structure of the investigated region. The obtained results speak in favour of the existence of a few separate blocks and a more sophisticated structure of the proposed Amurian microplate in comparison with an indivisible plate approach

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Analysis of geological and geophysical data on the boundary zones between the Eurasian plate and other plates shows poor knowledge of the deep structure of the region. This information will help to refine the position of the plate boundaries and the structure of the Earth’s crust and mantle. We present data on the seismicity and deep structure along the deep seismic sounding (DSS) profile running across the boundary between the Eurasian and Okhotsk plates. A comprehensive analysis of the DSS materials and seismic data shows a significant expression of this boundary zone both in the deep Earth’s crust structures and in the Moho. A zone of anomalous seismicity and deep structure extends along the DSS profile for several hundred kilometers. We have refined the position of the main boundary between the Eurasian and Okhotsk plates, which passes approximately along 144° E.

The recent geodynamics of the Far East region of Russia is considered, where three large tectonic plates converge—Eurasian, North American, and Pacific, as well as several microplates—Okhotsk, Bering, and Amurian—have been hypothesized to exist. The available data on the position of the plate boundaries, the relative plate rotation poles, and the regional seismicity were analyzed, and parameters of plate motion models for northeastern Russia were determined in this study. The regional deep structure was investigated, using data obtained by different geophysical methods. The results of observations of the Magadan–Vrangel Island profile by deep seismic sounding (DSS), common-depth point (CDP) method, and correlation refraction method (CRM) are presented.

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