Structural–dynamic model of the Chersky seismotectonic zone (continental part of the Arctic–Asian seismic belt)

Abstract

To construct a model for modern geodynamics of the Chersky seismotectonic zone (continental part of the Arctic–Asian seismic belt) we analyzed the available data on its structural–tectonic setting, depth structure, kinematics of active faults, morphotectonic features of modern topography, tectonic stress fields as derived from the earthquake focal mechanisms as well as the types of Late Cenozoic fold and rupture deformation. It is established that the Yana-Indigirka and Indigirka-Kolyma segments in the central part of the Chersky zone underwent transpression due to collision of the Eurasian (EU) and North American (NA) lithospheric plates. This was only possible if, in course of the plate convergence, the Kolyma-Omolon block in the frontal part of the NA plate formed the active indentor. Under the block pressure, geodynamic settings experience horizontal compression, in which case some of the blocks are being extruded along the system of northwestern and southeastern strike-slip faults. This results in the formation of major seismogenic structures with a high seismic potential in the marginal and frontal parts of the Chersky zone.