Contemporary Crustal Movement at the Southern Edge of Central Sikhote-Alin Fault According to GNSS-Observations

Abstract

The Central Sikhote-Alin Fault (CSAF) is one of the largest tectonic structures in the continental part of the south of the Russian Far East. Its modern geodynamic activity is still very poorly understood, especially by remote sensing methods. The available geological estimates of movements along the CSAR reach several mm/year, however, the available scattered modern geodetic data allow us to state that no displacements exceeding a few mm/year have been detected in the central part of the fault. In the present work, based on the data of GNSS observations carried out in the first two decades of the 21st century, the first quantitative estimates of the secular (plate) movements of the Earth's crust in the vicinity of the village of Kievka (Primorsky Krai), located at the southern end of the CSAR, are obtained. Also, in the study area, numerical modeling of the effect of geoenvironment disturbances (co- and postseismic displacements) initiated by the catastrophic Tohoku earthquake on March 11, 2011, Mw 9.1, was evaluated and performed. The results obtained are in good agreement with the available models of the earthquake source and models of postseismic viscoelastic relaxation of the geoenvironment.