The article discusses the observation methodology, data interpretation, and results of electromagnetic monitoring with a controlled source for one of the seismically active regions of Siberia-Gorny Altai. Monitoring was carried out during the aftershock period in the epicentral zone of the destructive 2003 Chuya earthquake with M = 7.3. For regular observations, a measurement technique has been developed using several modifications of the transient electromagnetic field (TEM) method to determine variations in electrical resistance and the anisotropy coefficient. Long-term series of these two geoelectric parameters of the section are presented, compared with the characteristics of ongoing seismic events. As a result of the analysis, it was shown that variations in electrical resistance and the electrical anisotropy coefficient ref lect the development and gradual decay of the aftershock activity of a powerful earthquake. The advantages of the TEM method and the selected technique for monitoring in complex areas are reflected.
