Efficiency of the Seismological Network in the North Caucasus

Abstract

The existing network of seismic stations in the North Caucasus consists of 37 instruments, but they are not evenly distributed on the territory. In this paper, we evaluated the effectiveness of this network, calculated and constructed maps of the distribution over the territory of the completeness of the energy class of recorded seismic events, and the error in determining the coordinates of their hypocenters. In general, the North Caucasian seismological network is quite effective. At different points in the region, earthquakes of different minimum energy classes and with different accuracy are recorded. In order for the observing system to record events occurring in different parts of the North Caucasus with the same accuracy and one minimum energy class, it is necessary that the seismic stations of the system be located more evenly throughout the territory; i.e., the observing system must have an optimal configuration. This optimal configuration was calculated, and the characteristics of the real and optimal networks were compared. Calculation of the minimum energy classes for the optimal magnification seismological network of the North Caucasus consisting of 32 seismic stations shows that with an increase of stations to 30 000, such a network throughout the territory of the North Caucasus confidently detects earthquakes of energy class 8.5 or greater, which corresponds to a magnitude of 2.5. At the same time, the position of seismic stations of the optimal network in the North Caucasus is determined accurate to a parallel shift and arbitrary rotation of the entire monitoring system. The error in determining the coordinates of earthquake epicenters in latitude and in longitude within the optimal network does not exceed 0.5 km. The error in determining the depths of earthquake sources in the center of such a network does not exceed 0.6 km, and throughout the territory of the North Caucasus it does not exceed 1.0 km.