DETERMINATION OF THE DYNAMIC AND FRACTAL CHARACTERISTICS OF TIME SERIES FROM A SEPARATE SEISMIC ENERGY SOURCE IN THE BALKAN PENINSULA

Abstract

The analysis of the dynamic and fractal properties of the released seismic energy time series allows for the classification of the seismotectonic system that produces earthquakes as a deterministic-chaotic system. The dynamics of such systems suggests that relatively small changes can lead to significant (with one or more order large) jumps. At the same time, the size of these jumps and the intervals of time that separate them are irregular, and the possibilities for their prediction are limited or absent. In this study for the analysis of temporal sequences of the emitted seismic energy, catalog data from independent events for the period 2009-04.03.2021 from the Athens University, combined with the Bulgarian catalog of earthquakes for the period 1981- 2019, were used. The studied period is from the beginning of 2009 to the end of 2019, including 214 730 earthquakes with Mw magnitude. A standard method for studying temporal sequences - spectral analysis - was applied. Time series of daily seismic energy release for the full range of magnitudes, as well as for various sub-ranges, were obtained. The frequency dependence of the spectral power S in a double logarithmic scale for the time series of the separated seismic energy in different ranges of magnitude was shown. For all analyzed time series, the Hurst exponent (H) and the fractal dimension (D) were calculated using the freely distributed program Fractan 4.4. Dependencies of log (R / S) on log (?) obtained for different ranges of magnitude and estimates of the Hurst exponent (H) were calculated. The standard deviations of the parameters are ?? 0.1, ?H 0.3, ?D 0.3. The fractal characteristics of the temporal sequences of the released seismic energy for the Balkan peninsula in different magnitude intervals were obtained.