## 4 Discussion  
The results of the analysis and comparison show that lithospheric magnetic anomalies of the SD profile have different degrees of correlation with the corresponding regional geological structure, lithology, seismic activity, remanent magnetization, and magnetic susceptibility. In area A, with the most earthquakes, the lithospheric magnetic field change is the most abrupt, and the lithologies are dominantly magmatic. In areas C and D, the seismicity is also intense. However, the variation in the lithospheric magnetic field in area D is gentle, and the seismic activity is high in the southernmost part, but the measuring points do not extend to that area. In the measured portion of area D, the Quaternary sedimentary cover is significant, which may explain why the variation in the lithospheric magnetic field is not higher. Based on the characteristics of the superficial f\({}_{\rm s}\) in combination with the location of metamorphic rocks among the rock samples, the superficial f\({}_{\rm s}\) of the SD profile has large magnetic anomalies 60 km south of the dividing line between regions A and B and 50 km north of the dividing line between regions B and C. There are some metamorphic rocks present in this location. The magnetic susceptibility and remanent magnetization values of the samples are also high in this location. Therefore, we conclude that the dividing line between regions A and B should be moved approximately 50-60 km to the south, or that the depth of the associated deep fault should be moved by this distance to the south. Additionally, the dividing line between regions B and C should be moved approximately 50 km north, or the depth of the associated deep fault should be moved northwards by this distance. However, more information is needed to be certain of this viewpoint. Seismicity has been observed in relation to lithospheric magnetic anomalies in seismically and tectonically active zones. [PERSON] et al. employed the morphostructural zoning missing space method in combination with the World Digital Magnetic Anomaly Map (WDMAM) International Scientific Project to obtain lithospheric magnetic anomaly data in the region of Altai-Sayan-Baikal [36]. Their results show that the locations of strong earthquakes are related to the geological structure and lithospheric magnetic anomalies in the region [37; 38]. The Altai-Sayan-Baikal region is located on the northwest boundary of the SD profile. The results of this research have guiding significance for understanding the magnetic structure, geological structure, and seismicity of the SD profile. Therefore, it is necessary to analyze the relationship between the characteristics of lithospheric magnetic anomalies and their changes and earthquakes in seismomagnetic research. The upward continuation data processing method is used here to decompose lithospheric magnetic anomalies into the basement f\({}_{\rm b}\), middle layer f\({}_{\rm m}\), and superficial f\({}_{\rm s}\) portions as an approximation of the anomalies at different depths underground. The attenuation rate of shallow-source anomalies is faster than deep-source anomalies after upward continuation, but the data from upward continuation cannot perfectly reflect the anomalies at different depths. Notably, large surface anomalies undoubtedly affect the results of upward continuation. In the field survey process, we strictly measured the gradient around the site. The environmental magnetic field gradient at each site was small, greatly reducing the possibility of involving large superficial anomalies. The obtained results do not affect our approximate estimation of the magnetic properties of the deep rocks, and they facilitate the