Seismic instruments: article

Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences
Journal: Seismic instruments
Tome: 56
Number: 2
Year: 2020
Pages: 5-14
UDK: 550.312
DOI: 10.21455/si2020.2-1
Аnnotation file
Bibliographic list
Keywords: seismic stations, observing system effectiveness, earthquake energy class, earthquake magnitude, hypocenter, optimal observing system, North Caucasus
Аnnotation: 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, 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 are located more evenly throughout the territory, that is, the observing system must have an optimal configuration. This optimal configuration was calculated, and the characteristics of the real and optimal networks were compared. The calculation of the minimum energy classes for the optimal seismological network of the North Caucasus from 32 seismic stations shows that with an amplification in stations of 30 thousand such a network throughout the territory of the North Caucasus confidently detects earthquakes of energy class 8.5 and more, which corresponds to magnitude 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. Error values in determining the coordinates of earthquake epicenters in latitude and in longitude within an optimal network do not exceed 0.5 km. The error values in determining the depths of earthquake sources in the center of such a network do not exceed 0.6 km, and throughout the territory of the North Caucasus it does not exceed 1.0 km.