Table 1 - uploaded by O. V. Pavlenko
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For evaluating the parameters of the vibrations of the Earth’s surface in the case of strong earthquakes, which are possible
in the future, the regular patterns of the emission and propagation of seismic waves in the North Caucasus regions are investigated.
The regional parameters of emission and propagation of seismic waves are evaluated by soluti...
Contexts in source publication
Context 1
... records of earthquakes with moment magnitudes å w ≥ 3.9, recorded by the seismic station of Sochi in the last five years, from 2002 until 2006, i.e., practically all available up-to-date high-quality records of the seismic sta- tion of Sochi were analyzed. The data on these earthquakes are given in Table 1. The moment magnitudes are evaluated according to the data of the Geophysical Service of the Russian Academy of Sciences on the class of earthquakes by the empirical formulas, obtained for the North Caucasus by A.I. Lutikov [Lutikov, 2006]. ...
Context 2
... work was supported by the Russian Founda- tion for Basic Research, project No. 09-05-01045a. Table 2. Parameters, used for simulation of accelerograms of the earthquakes, recorded by the seismic station of Sochi Coordinates and depths of hypocenters Presented in Table 1 Stress parameter 50 bar Geometrical divergence 1/R for R < 70 km 1/70 for 70 ≤ R < ...
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The dynamic parameters of the sources of 44 earthquakes in the North Caucasus were determined from the amplitude spectra of S-waves for the period 2018–2019 with an energy class according to T.G. Rautian scale KR=9.1–14.1. Earthquake records from regional digital seismic stations of the North Caucasus network, with epicentral distances of no more than 300 km were used for the calculation. The source spectra were calculated based on the frequency-dependent quality factor Q(f) for earthquakes in the North Caucasus western zone – Q(f)=90f 1.02 – and eastern zone – Q(f)=97f 0.89 . The SEISAN program was used for the spectral analysis of 31 earthquakes. The following values were obtained: 0 – spectral density, f0 – corner frequency, M0 – scalar seismic moment, Mw – moment magnitude, L – length of the rupture at the source of an earthquake, or r – radius of the circular area, – stress drop. Relationships between lgM0 and KR and Mw and KR are obtained.
The source spectral and dynamic parameters for 39 earthquakes with KR=10.0–13.8 occurred in the North Caucasus for 2016–2017 are given. The parameters were determined from S-wave amplitude spectra. Records of four regional digital seismic stations («Anapa», «Kislovodsk», «Makhachkala» and «Sochi») located no more than 300 km from the sources were used. The values of the frequency-dependent quality factor Q(f) for the environment near these stations were obtained earlier. This is necessary to take into account the attenuation of S-wave energy in the Earth's crust and upper mantle in order to recalculate the station spectra into the source spectra. In 2016–2017, most of the studied earthquakes were located in the Eastern Caucasus. For the first time, for western zone earthquakes recorded by a network of stations (N=4–7), the SEISAN program was applied and satisfactory results were obtained when compared with the Crimean data for the Kerch-Kuban zone.
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The dynamic sources parameters of 29 earthquakes of the North Caucasus for 2015 with KR=9.5–11.4, determined from 38 S-wave amplitude spectra are analyzed. Records of four regional digital seismic stations, “Anapa”, “Kislovodsk”, “Makhachkala” and “Sochi”, located no more than 300 km from the sources are used. For the environment near these stations, the values of the frequency-dependent Q-factor, necessary for recalculating the station spectra to the focal ones. In 2015, the majority of earthquakes studied were located in the Eastern Caucasus. The dependence between log M0 and KR for this zone was constructed using together with the data for 2010–2014.
Dynamic sources parameters of 21 earthquakes of the North Caucasus for 2014 with КР=9.5–11.5, determined from 44 S-wave amplitude spectra are analyzed. Records of three regional digital seismic stations, “Anapa”, “Kislovodsk” and “Sochi”, located no more than 300 km from the sources are used. For the environment near these stations, the values of the frequency-dependent Q-factor, necessary for recalculating the station spectra to the focal ones, were obtained earlier by O.V. Pavlenko. In 2014, the majority of earthquakes studied were located in the Eastern Caucasus. The dependence between log M0 and КР for this zone was constructed using the data for 2010–2013. Compared to the similar equation for the entire Caucasus (Riznichenko et all., 1976), this dependence is in a good agreement with respect to the free term, but differs by the slope.
The dynamic parameters of of 18 earthquakes sources in the North Caucasus for 2013 with КР=10.0–12.9, determined from 64 amplitude spectra of S-waves are given. Records of three regional digital seismic sta-tions, “Anapa”, “Kislovodsk” and “Sochi” are used. They are located no more than 300 km from the sources. The records of the “Makhachkala” station were used in a test mode. For the environment near these stations, the values of the frequency-dependent Q-factor, necessary for recalculating the station spectra to the focal ones, were obtained earlier. In 2013, the largest number of studied earthquakes was located in the Eastern Caucasus. The dependence of log M0 and КР for this zone was established with use of the data ob-tained in 2010–2013. Compared to the similar equation of world average dependence (Riznichenko, 1976), our dependence is in a good agreement with it by the slope, but the free term exceeds the same in the world average dependence by almost two units.
