Аннотация:Abstract—Earlier, the authors carried out a unique experiment on long-term continuous precision monitoring of crustal resistivity variations in a highly seismic region. The result of this experiment can be considereda special type of VES profile, in which, instead of a linear coordinate, the sounding date changes from markerto marker. When processing precision monitoring data, it is necessary to solve the inverse VES problem withthe highest possible accuracy. Standard programs for inversion of VES curves do not allow this, and even withvery small fitting residuals, the actual error in reconstructing the resistivity can be huge due to equivalenceeffects. The authors have previously developed a special method for regularizing the residual functional,which multiply increases the accuracy in solving the inverse problem for the considered type of resistivity section, and a method for obtaining realistic, rather than underestimated estimates of the solution error. To dothis, a package of synthetic resistivity profiles is formed that imitates a real section, the VES direct problemis solved, and time series of apparent resistivity are constructed, on which noise similar to real noise is superimposed. After that, the VES inverse problem is solved and the errors in reconstructing the model resistivitycurves are analyzed. Such calculations were carried out both for the total signals and their components,obtained as a result of decomposition of the apparent resistivity series into physically determined components. The developed approach makes it possible to solve the inverse VES problem with heretofore unattainable accuracy. We emphasize that a reliable estimate of the solution errors is provided not by the convergencecriteria of the inversion algorithm (they are almost always overly optimistic), but by direct calculations of thedirect and inverse problems for synthetic profiles similar to real signals. In the present article, the profile ofthe experimental VES curves obtained in the course of this experiment is inverted. Series of resistivity variations are calculated in four layers of a geoelectric section with a duration of more than 12 years. It has beenestablished that the upper layer of the section is characterized by trend and seasonal changes in resistivity witha large amplitude. Significant anomalous seasonal effects were found in the second layer of the section. Forthe third layer, the presence of small-amplitude seasonal effects was established, while there are no significantresistivity trends. Variations in the resistivity of the fourth layer are less reliably estimated; to detect the effectsof external factors on electrical resistivity, it is necessary to use signal stacking methods.
