Geodynamics and seismicity of the eastern part of Central Asia

Study of the geodynamics of the eastern part of Central Asia shows that the present-day tectonic activity of this territory is connected with its division into blocks limited by active faults and with the interaction among these blocks and with the neighboring lithospheric plates. The North China and South China platforms occupy most of this territory. The western boundary of the South China platform with Tibetan blocks is the most active. The energy volume increases up to 10¹⁰–10¹² J, and the earthquake magnitudes go up to 8–9 within this boundary. The interaction of Tibetan blocks with the Southeast China Block causes detachment and a clockwise turn of the upper layers of the Earth’s crust under the influence of the Hindustan indenter pressure.

     

On the Problem of Distinction between Recent Geodynamics of Central and East Asia

Izvestiya, Physics of the Solid Earth - Abstract—The Central Asian and East Asian transitional zones are distinguished in Central and East Asia south of the Late Precambrian–Paleozoic...     

Zones of the origin of seismic centers in the Pamir–Tien Shan sector of High Asia

The zones of the origin of seismic centers within highly seismic areas of the Pamirs and Tien Shan are established. The majority of catastrophic earthquakes coincide with them in this part of High Asia. Their establishment is based on the distribution of the most intensive epicenters and the maximal volumes of the seismic energy together with its calculation and forecasting of the possible manifestations of high seismicity. The investigation of the deep structure of these zones allows us to determine the connection of the seismicity with geophysical field anomalies and some factors of the deep and near surface lithosphere and crust structure, which influence the present-day geodynamics. The results of our research enable us to appreciate the level of the seismic danger in different parts of the region investigated.     

Block structures and kinematics of Western Eurasia according to GPS data

The transitional Alpine-Iranian and North African-Apulian zones, which extend between the North Eurasian, Arabian, and African lithospheric plates, are composed largely of crustal blocks bounded by seismically active faults and, as follows from the data of satellite geodesy, are characterized by the variously directed present-day motions of these blocks. The measured horizontal displacements of the largest blocks in the ITRF system are compared with motions of the main lithospheric plates suggested by the NNR-NUVEL-1A model. The established discrepancies are related to the deformation of blocks in the transitional zones between interacting plates, a circumstance that is consistent with relative block displacements. The close coincidence of the measured and the model velocities of horizontal motions at observation points in western Europe beyond the alps allows us to extend the North Eurasian Plate to the west of the Rhine Grabens. The systems of intraplate active faults are considered, and the depth of that surface, along which tectonic blocks move in the horizontal direction, is estimated.