Spatial and time variations of seismicity before strong earthquakes in the southern part of the Balkans

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Emil Iliev Oynakov
https://orcid.org/0000-0002-8992-5581
Emil Aleksandrov Botev

Abstract




A retrospective analysis of the spatial and time variations of three main statistical parameters of the seismicity before recent 4 stronger earthquakes (2015 – 2020) in the southern Balkans is presented. The modern extended software package ZMAP with various advanced seismological functions for earthquake catalog analysis is used for estimating the spatial-time variations in a- value (seismic activity), b-value (slope of the recurrence graph) and z-value (parameter of the relative seismic quiescence). The catalog data from constantly updated catalog of the University of Athens for the period 1964-2020 and spatial window 32° - 44° N and 10° – 30° E are used for the various statistical interpretations. The main result of the whole analysis is that the abnormally low b-values and high z-values, defining the zones of relatively seismic quiescence, may be an indicator of imminent release of more significant stress in areas adjacent to the zones of relatively high a-values. Thus, the result of the proposed joint interpretation of the spatial-time variations of these three statistical parameters of seismicity could be considered as a kind of predictor of the stronger recent seismic events in the southern part of Balkans.




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How to Cite
Oynakov, E. I. and Botev, E. A. (2021) “Spatial and time variations of seismicity before strong earthquakes in the southern part of the Balkans”, Annals of Geophysics, 64(4), p. SE433. doi: 10.4401/ag-8566.
Section
Seismology