ON SIMILARITIES BETWEEN DEFORMATION PROCESSES PRECEDING ICE SHOCKS AND TECTONIC EARTHQUAKES

Abstract

The instrumental monitoring reveals an autowave nature of ice deformation behavior prior to ice shocks. A few minutes or the first tens of minutes before the shock, this process shows an increase in the amplitude of oscillations, often with a multi-fold reduction in their period. An autowave dynamics of ice deformations is due to self-organization of a structurally heterogeneous ice environment under critical conditions. The self-organization ability of the deformation process is confirmed by the results of ice deformation time series processing by the structural function curvature analysis method (SFCAM) and by the Lomb-Scargle periodogram method. The results of seismic monitoring of ice showed that autowave processes are characterized by constant frequency of 0.1 Hz. Taking into account the ice deformation and microseismic fluctuation features preceding the ice shocks, spectral analysis was performed on the data of deformation and seismicity monitoring at the Buguldeika geodynamic polygon before the Kudara earthquake. According to the results, 14 hours before the earthquake the seismogram recorded a gradual increase in auto-oscillation amplitudes in the frequency range from 0.01 to 0.1 Hz. The maximum amplitude increase is 19.5 against the background.