Insights into seismicity from the perspective of the crustal stress field: a comment

Knowledge of the crustal stress field is critical to understanding the driving forces and processes responsible for seismicity. The purpose of this article is to systematically comment on the interaction between the stress state and seismicity, as well as the potential application value and limitations of stress/strain observations in earthquake research. In situ stress measurements and stress/strain monitoring have been employed to detect the stress/strain anomalies and the corresponding earthquake precursors, and great progress has been made. There are some correlations between seismicity and the stress field from stress monitoring before and after an earthquake. However, the relationship between stress changes and the mechanism of earthquake genesis cannot be well explained because of a lack of strong evidence. Moreover, the extremely shallow depth of stress/strain measurements relative to the focal depth limits the efficacy and persuasiveness. Therefore, it is necessary to master the mechanical state and strain energy accumulation at the earthquake source during the adjustment of the regional stress field in earthquake prediction. In addition, emphasis should be placed on investigations of the genesis of abnormal stress/strain and action mode and scope of the stress/strain to study the mechanism of earthquake precursor anomalies and earthquake focal mechanisms.