Identification of the Nature of Seismic Events that Occurred in the East European Platform as Recorded by the Mikhnevo Small-Aperture Seismic Array at Regional Distances

Abstract

This article summarizes the observations of the Mikhnevo small-aperture seismic array (SSA) for seismic events within the East European Platform based on analysis of a large number of experimental data. A method for recognizing earthquakes and short-lived group blasts, which is based on discriminating the nature of slope for the curve of distribution of the ratio between amplitude spectra of P and Lg waves log(AP/ALg) relative to the frequency of oscillation, is proposed. It is shown that the curve has a certain trend, whose slope is different for explosions and earthquakes. A new criterion, that is, the sign of the coefficient in the equation that connects the values of log(AP/ALg) and the frequency, is proposed. A negative trend with the increase in frequency is typical of short shots, while a positive trend is typical of earthquakes. The method has been tested based on the records of 405 industrial explosions and 24 earthquakes, with epicenters located 350–900 km from the Mikhnevo SSA.