RUSSIAN JOURNAL OF EARTH SCIENCES VOL. 11, ES1001, doi:10.2205/2009ES000326, 2009

Zones of catastrophic earthquakes of Central Asia: Geodynamics and seismic energy

Vernadsky State Geological Museum RAS, Moscow, Russia

T. V. Prokhorova, G. L. Vladova

International Institute of Earthquake Forecast and Mathematic Geophysics, Moscow, Russia

Abstract

Central parts of the Asian continent are characterized by abnormally high seismic activity, which spreads not only along collision and subduction zones but also at withdrawal from them in inner continental regions. The majority of earthquakes' epicenters are situated along active faults, indicating boundaries of blocks in transit zones, which divide the main lithosphere plates and provide transfer and relaxation of tectonic stresses that arise between them. Such zones partly coincide to well known "diffuse plate boundaries". In central and east Asia there are the Central Asian, East Asian, and some smaller transit zones, which consist of numerous crust or crust-mantle blocks. Block boundaries are represented in the zones by not only single faults, but often by relatively wide interblock zones. Just in these zones movements of blocks and plates are realized as accumulation of the tension, which relaxes in the future as earthquakes, including the majority of catastrophic events. One can see in such zones a certain analog of transit zones between main plates that reflects a fractal structure of the continental lithosphere. Maximal volumes of the seismic energy release within interblock zones limiting such blocks as Pamir, Tien Shan, Bayanhar and the north boundary of the Indian Plate in the Central Asian Transit Zone, as well as within boundaries of the Japanese-Korean Block and partly the NW boundary of the Amurian Block in the East Asian Zone. Interblock zones in our interpretation are partly similar to "destructive zones of lithosphere" and "mobile zones", which also divide blocks of different sizes according to other scientists. Our investigation is devoted to the detaile examination of the most active interblock zones, distinguishing levels of the maximal seismic energy releasing in them and regularities of its dissipation. The examination of the zones is closely connected with the prediction of catastrophic earthquakes' possibility in some regions of central Asia that can be demonstrated at the example of the Wenchuan earthquake in south China in May 2008.

Received 30 October 2009; accepted 6 November 2009; published 11 November 2009.

Keywords: Central Asia, earthquakes, geodynamics, seismic energy, catastrophic event, transit zones, interblock zones of lithosphere

Citation: Gatinsky, Yu. G., T. V. Prokhorova, D. V. Rundquist, and G. L. Vladova (2009), Zones of catastrophic earthquakes of Central Asia: Geodynamics and seismic energy, Russ. J. Earth Sci., 11, ES1001, doi:10.2205/2009ES000326.