Variation of displacement fields and Gorny Altai seismic regime

More than twenty years of crust motion measurements by space geodesy method include different epochs of Gorny Altai seismic process. Our study aims at investigating the fields of displacement and deformation in the Gorny Altai region, where we have 20 points-net, situated on big territory, from Novosibirsk in North to Molgolian border at South, and from Kazahstan border at West, to Sayan Mountains at East. Chuya earthquake (September, 2003) separated study period (2000‒2022) to several epochs: pre-seismic – 2000‒2003; 2003‒2004 co-seismic period for epicentral zone; 2004‒2013 post-seismic period for epicentral zone and 2000‒2022 period for far-zone without of earthquake influence. Long term data analyses by modern special program. Anomalous behavior features are discovered in the displacement orientations, as well as in the distribution of velocities and deformation in the zone of the future earthquake. The spatial displacement pattern defined for the period of coseismic displacements corresponds to the right‐lateral strike‐slip along the vertical fault. Elastic and viscoelastic models (2D and 3D modification) used for interpretation. Depth of hypocenter was estimated as 14 km with 2 m relative shift on the seismic fault. In frame of two layers model the viscosity of lower crust ranges 5·1019‒1.1·1020 Pa·s for different elastic modulus parameters. The results of our study show that modern horizontal displacements occur in the NNW direction at the rate of 0.8 mm/y for mountain part outside the Chuya earthquake epicenters zone. Velocity of area deformation at mountain part was 2·10–8/y and it is one order more than the value at flat territory situated to North from Gorny Altai.