Dislocations caused by ancient strong earthquakes in the Elbrus region

Abstract

The probability of natural disastrous phenomena in the Northern Caucasus is a topical scientific problem. According to materials of the Map of General Seismic Zonation of the Russian Federation, the Elbrus region belongs to the seismic impact zone with a magnitude of as much as 8 or 9 [1]. Estimation of seismic risk for the Caucasian region based on the cluster analysis of geological–geophysical and seismological data [2] showed that the Elbrus region includes a potential seismic focus (PSF) with a predictable maximal magnitude of expected earthquakes equal to 7.2 [3]. At the same time, the region also incorporates a vast calm zone in terms of seismicity, for which any instrumental and macroseismic data on earthquakes are absent. This situation is accounted for by the fact that the melt in a vast magma chamber existing at present beneath Mt. Elbrus in the central part of the Earth’s crust [4–6] promotes the stress relief. Therefore, strong seismic quakes do Dislocations Caused by Ancient Strong Earthquakes in the Elbrus Region E. A. Rogozhin, A. N. Ovsyuchenko, and A. V. Marakhanov Presented by Academician S.A. Fedotov August 17, 2007