On some features of geoacoustic emission signals before earthquakes

Abstract

Geoacoustic emission signal amplitudes and arrival directions were analyzed during background periods and earthquake preparation. It was determined that during seismic event activation, geoacoustic emission directivity anisotropy increases with the increase of signal amplitude. Taking this feature into account, geoacoustic emission properties were estimated by the superposition method before 2653 earthquakes which occurred within the period from 01.01.2008 to 01.09.2016. It was determined that depending on the type of the signals under consideration, it is possible to detect geoacoustic emission anomalous behavior at the distances of more than 25% and 65% of the precursor manifestation zone radius suggested by I.P. Dobrovol'skiy.