Dislocations Caused by Ancient Strong Earthquakes in the Elbrus Region

摘要

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 mac-roseismic 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.