Modern tools of analyzing azimuthal magnetotelluric monitoring data at the Bishkek Geodynamic Polygon Test Site

The paper presents a methodology for processing magnetotelluric (MT) monitoring data adopted since 2010 at the Bishkek Research Station of the Russian Academy of Sciences (RS RAS). The proposed methodology differs from the standard one as it evaluates impedance relationships after amplitude-phase correction within hourly files of MT sounding obtained from a continuous raw record from stationary and regime stations of the RS RAS network. Modern additions, add-ons, and the creation of additional programs made it possible to adapt and automate the receipt of time-frequency series (TFS) in the form of relative variations of various calculated electromagnetic parameters as color pseudo-sections, as well as adding complementary input information for additional analysis of ongoing geodynamic events. The usage of the patented MT-Corrector and EPI-KIT software packages, developed by Nord-West Ltd., made it possible to automate the acquisition of impedance and phase ratios for TFS post-processing. Integration of data on tidal effects, electromagnetic field characteristics of endogenous origin, and seismic activity ensures correlation between the dynamics of geophysical parameters and the stress–strain state of the medium. The developed toolkit facilitates the identification of stress-sensitive zones, registration of spatiotemporal anomalies, and forecasting of fault activation processes. The obtained results confirm the efficiency of the proposed approach for comprehensive monitoring of geodynamic processes by MT data in tectonically active regions.