Abstract:
The statistical analysis is applied to study the temporal distribution of the aftershock activity observed after the earthquake of February 21, 2018 with moment magnitude MW 4.7, realized in the area of the city of Asenovgrad, Maritsa seismogenic zone. Based on the assumption that the aftershocks are distributed in time as a non-stationary Poisson process, the modified Omori formula is used to estimate the parameters (K, c and p). The transformation of the time scale t to a frequency-linearized scale τ is applied to determine the best relationship between the aftershock activity and various statistical models. The decay of the aftershock activity is well described by the modified Omori formula, and a multipole activity with two secondary series is observed.