## 2 Materials and Methods
### Electromagnetic Monitoring of Strain-Sensitive Zones in the Tien Shan
\begin{array}{l}Z_{xy}(\alpha)=Z_{xy}\cos^{2}\alpha-Z_{yx}\sin^{2}\alpha- \left(Z_{xx}-Z_{yy}\right)\sin\alpha\cos\alpha,\\ Z_{yx}(\alpha)=Z_{yx}\cos^{2}\alpha-Z_{xy}\sin^{2}\alpha-\left(Z_{xx}-Z_{yy} \right)\sin\alpha\cos\alpha,\end{array}  \tag{1}\]  
where \(Z_{xx}\), \(Z_{xy}\), \(Z_{yx}\), and \(Z_{xx}\) are the components of the impedance tensor **Z = E/H** in the respective directions (corresponding to their first index), \(E_{x}=Z_{xx}H_{x}+Z_{xy}Hy\); \(E_{y}=Z_{yx}H_{x}\) + \(Z_{yy}H_{y}\). The orientation of the impedance components aligns with the orientation of the electromagnetic field components, and \(\alpha\) represents the clockwise rotation angle of the axes. The methodology for processing MTS monitoring data is detailed in [31; 49]. Figure 1 shows the network of monitoring points (deep MTS points) in the northern Tien Shan region. Figure 1: The monitoring network of the Research Station of the Russian Academy of Sciences in Bishkek in the central Tien Shan, along with the Kambarata point, on a geographic elevation map. The network includes various types of monitoring points: stationary points, regime monitoring points, and points of deep magnetotelluric soundings. The key features depicted in Figure 1 are as follows: 1—Aksu and Chon-Kurchak stationary points, Kentor mini-polygon, and Ukok regime monitoring point; 2—cities; 3—fault structures; 4—borders of the Kyrgyz Republic; 5—point of explosion at the Kambarata point; 6—points of deep MTS. To represent the results of monitoring data processing, we utilized time-frequency series (TFS), which visualize the variability in measured electromagnetic field components with depth (logarithm of the sounding period) as the coordinate system is rotated by a certain angle (in degrees). Previously, some results showed good evidence of temporal variations. A widely researched study that is a very powerful example of a geodynamic man-made event with all known parameters (time, yield, volume) associated with initiated geodynamic natural events is the Kambarata blast-fill dam experiment. Figure 2 displays the TFS for the Kambarata point (top left panel in Figure 1) with a rotation step of \(\alpha=15^{\circ}\) azimuth. The TFS shows the variations in apparent resistivity (\(\Delta\rho_{k}\)), which represents the difference between the average and current values along the considered azimuth within a 72 h period [31, 49]. This initial step allows for the analysis of anisotropy in physico-electric parameters under different coordinate system orientations over continuous time. It is evident that the variations (\(\Delta\rho_{k}\)) occur and exhibit uniqueness over time. These variations are influenced by changing telluric currents due to external factors such as lunar-solar tides, fluid dynamics, or man-made impacts on the lithosphere, as observed at the Kambarata point. The Kambarata 2 blast-fill dam is located in the geodynamically active and seismic part of the central Tien Shan [50]. The Kambarata explosion, which occurred on 22 December 2009 at 11:54 UTC in Kyrgyzstan (coordinates of the main explosion measured by GPS: 41.77467\({}^{\circ}\) N, 73.33122\({}^{\circ}\) E), was an exceptionally powerful event for geophysical monitoring. The explosion had a total yield of 2800 tons of TNT equivalent. Additionally, another form of MTS monitoring data is represented in polar diagrams, which depict changes in electromagnetic parameters over a specific time period. Figure 3 demonstrates the behavior of apparent resistivity (\(\rho_{k}\)) before and after the Kambarata industrial explosion and subsequent earthquakes [31, 49]. These polar diagrams serve as circular sounding monitoring tools that remain invariant regardless of the orientation of the instrument installation. This represents the second step in analyzing physico-electric parameters with sounding period parameters. Geodynamic processes manifest in the geological media as a result of stress and state imbalances.