Structural-Dynamic Model of Constituent Segments of the Seismotectonic Chersky Zone (Continental Part of the Arctic-Asian Seismic Belt)

Imaeva L.P., Imaev V.S., Kozmin B.M.

To create a model of modern geodynamics of the seismotectonic Chersky zone (continental part of the Arctic-Asian seismic belt) we analyzed its structural-tectonic position, parameters of a deep structure, kinematic types of seismogenic structures, morphotectonic features of the modern relief and  corresponding to them tectonic stress fields established on a basis of the solutions of focal mechanisms of local earthquakes  centers, as well as the types of the Late Cenozoic fold and discontinuous deformations. It was found that under the transpressional conditions (compression with strike-slip) within the local segments of the central part of the  Chersky zone (Yana-Indigirka and Indigirka-Kolyma) there is a certain dynamic situation, initiated by the interaction of the frontal structures of the contact zones of the Eurasian and North American lithospheric plates. Such conditions are possible if during the convergence of  these plates the Kolymo-Omolon block in the frontal part of the North American plate as the indenter was active. Under the pressure of the indenter a series of terrains of different geodynamic nature was exposed to horizontal compression. As a result individual blocks of those segments on the system of differently directional strike-slips of different hierarchy were extruded in lateral direction along the orogenic belt respectively to the north-west and the south-east, forming on the edges and front parts of the Chersky zone the main seismogenic structures with a maximum seismic potential.

Key words: Arсtiс-Asian seismic belt, seismotectonic Chersky zone, regional segments, active faults, mechanism of earthquakes, types of Late Cenozoic deformations, Kolyma-Omolon block, indenter, dynamics of seismogenic structures, structural-dynamic model.

Science and Education, 2015, No.1, pp.22-30