© I. A. Larionov, A. O. Zherbina, M. A. Mizhenko

Institute of Cosmophysical Researches and Radio Wave Propagation (IKIR) FEB RAS, 684034, Paratunka,
Kamchatskaya oblast, Elizovskiy region, Mirnaya st., 7, Tel. /Fax: (415-31) 33-7-18, [email protected]
Correspondence address: 684034, Paratunka, Kamchatskaya oblast, Elizovskiy region, Mirnaya st., 7
Tel. /Fax: (415-31) 33-7-18, [email protected]

On the basis of two directional hydrophone systems installed at the distance of 20 km from each other, one is in an artificial reservoir and the other one is in a lake, long-lasting observations of the geoacoustic emission in the frequency range 0.1-10000 Hz aiming at discovering and researching the changes in the characteristics of geoacoustic noise, which corresponds to the final stage of seismic events development. The observations showed, that in some cases in high-frequency part of the spectrum during a day before an event, considerable and long increase of signal was observed. This increase exceeded repeatedly the background level. A comparative analysis of high-frequency disturbances, registered simultaneously at different sites, was carried out in order to distinguish common characteristics. It was showed that the value and also the appearance of anomalous signal of geoacoustic emission, preceding strong seismic events, depend not only on the energetic class, depth of an earthquake focus and the distance to the epicenter of a preparing earthquake but also on the location of receiving systems themselves and on the way of installation. One can suppose that simultaneously appearing high-frequency anomalies of geoacoustic emission at spaced sites are determined by deformational processes activating before a seismic event.