The monitoring of media state in the subduction zone. Possibilities for short-term seismic hazard estimation

Abstract

The paper considers the non-barrier seismic process in the subduction zone associated with the violation of accommodation of elements in the active medium relative to each other. The authors use special methods for the monitoring of media with internal sources of energy controlled hydrogen degassing. Two main modes of oscillatory processes were revealed in subduction zones. Based on the analysis of the seismicity of the Kuril-Kamchatka area and the Japanese Islands the authors show short-term features of the oscillatory mode of the environmental elements prior to possible megaseismic events. The reliability of conclusions is confirmed by the solutions analysis of the evolution equation of the medium state. The investigation resulted in diagnosis of pre-catastrophic state of the medium, which allows controlling the transition from the background into the short-term mode with the highest probability of the strongest seismic events as well as detecting in short-term hazard the epicentral area of the strongest seismic events in subduction zones.