In respect to tectonics, the epicentral zone of the Chuya (Altai) earthquake is located in the region of bifurcation of the northward rock mass flow generated by the Indo-Eurasian collision. When the flow runs into hard rocks at the southern boundary of the West Siberian Plate, it is split into two parts. One part moves to the southeast and further to the east along the western Sayan-eastern Sayan profile, while the other part spreads to the northwest and west. The source zone of this earthquake is located in the eastern part of the northwestern flow (almost at its border) (Fig. 1). Since 2000, recent motions in Gornyi Altai have been investigated using the GPS technology. We present results of these investigations taking into account the Chuya earthquake (September 27, 2003, 49.999° N, 87.856° E, M = 7.3-7.5). We put forward the following objectives: (1) identification of effects preceding the earthquake; (2) compilation of the pattern of displacements after the earthquake; (3) examination of the correspondence of the displacement field to the mechanism of elastic response.
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