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The article deals with the first results of integrated geohazard monitoring conducted by the Institute of the Earth’s Crust SB RAS on the territory of Pribaikalye in 2020. The pilot network consists of three sites: "Buguldeika", "Priolkhonye" and "Listvyanka", each of which is equipped with high-precision digital devices including a broadband seismic station, a GPS receiver, deformometers, a sensor of soil radon emanations, and an observation station for the Earth’s electromagnetic environment. This equipment is designed to acquire quantitative information on rock deformation, recent movements and geophysical field variations for solving theoretical and applied problems of geodynamics and seismology, including development of earthquake prediction methods. In the vicinity of the sites, there have been made the hydroisotopic measurements as well as observations over the character of some of exogenous processes. Based on the comprehensive analysis of the seismological, tectonic, deformation and emanation data, acquired also through monitoring, there has been obtained the preliminary characteristics of the Kudarinsky earthquake (December 9, 2020, MW=5.6) that was followed by intensity 5 aftershocks in large cities of the southeastern East Siberia – Irkutsk, Shelekhov, Angarsk, Usolye-Sibirskoe and others. It has been found that the seismic event manifested itself almost in all the fields monitored. This implies the network efficiency for a purposeful study of the precursors of large earthquakes which can initiate the development of other hazardous geological processes in Pribaikalye. The deformation monitoring data show some general patterns of earthquake source evolution which corresponds to the fundamental principles of physical mesomechanics. This opens the prospects for diagnostics of the final phase of earthquake generation in the context of meta-instable state of deformation process and rock mass disintegration.

The Southern Baikal is located within the actively developing Baikal rift zone (BRZ) that is characterized by a significant seismic potential, and M>7 earthquakes occur periodically with intensive shaking in the epicenters (up to 10 units). The problem of prediction and forecasting of strong earthquakes has always been critical for this region, considering its increasing urbanization, industrial clusters and transport systems. The article describes the methodology based on rock deformation monitoring data, which aims at developing a technology capable of efficient prediction and forecasting of strong earthquakes. In the Institute of Earth’s Crust SB RAS a set of studies is carried out in order to solve this problem, including those associated with the instrumental study of current movements of the lithosphere through GPS geodesy and deformations of rocks by strain gauges. The existing GPS sites and deformation measurements are combined into the Large-Scale Research Facilities "South Baikal instrumental complex for monitoring hazardous geodynamic processes" in frame of the Shared Research Facilities "Geodynamics and Geochronology" at the Institute of the Earth’s Crust, Siberian Branch of the Russian Academy of Science.In this article, the deformation monitoring methodology is described in application to the monitoring sites installed in the study area. The description includes the details of its conceptual basis, technical support and data processing methods. The discussion focuses on the instrumental measurements of rock deformation related to three strong events in the study area – Kultuk (August 27, 2008), Bystrinskoe (September 21, 2020), and Kudara (December 10, 2020) earthquakes. The features of the deformation process before these seismic events are given special attention with account of the structural-geodynamic settings and positions of local monitoring sites relative to the earthquake epicenters.

Based on the results of a laboratory simulation of the seismic fault reactivation by “stick-slip” process, it was shown that the system of two blocks just before an impulse offset goes through the meta-instable dynamic state, with early and late stages of meta-instability [Ma et al., 2012]. In the first stage the offset begins in slow stationary mode with slow stresses relaxation on contact between blocks. In the second stage of the “accelerated synergies” strain rate increases and, subsequently, the deformation process through a process of self-organization came to dynamic impulse offset. The experimental results were used for interpretation of the results of spectral analysis of the deformation monitoring data. The data were held within the southern part ofLakeBaikal, where Kultuk earthquake (27.08.2008, Ms=6.1). took place. Its epicenter was located in the South end zone of the main Sayan fault. Monitoring of deformations of rocks was carried out from April to November2008 in tunnel, located at30 km from the epicenter of the earthquake. The time series data was divided into month periods and then the periods were processed by the method of spectral analysis. The results showed that before the earthquake has ordered view spectrogram, whereas in other time intervals, both before and after the earthquake such orderliness in spectrograms is missing. An ordered view spectrograms for deformation monitoring data can be interpreted as a consequence of the self-organiza­tion of deformation process in the transition of seismically active fault into meta-unstable before the Kultuk earthquake.