Abstract：We analyze the spatial variation characteristics of horizontal vector anomaly of lithospheric magnetic field in Sichuan from 2010 to 2014. The results show that the weak variation area of horizontal vector of lithospheric magnetic field has a good correspondence with moderate-strong earthquakes, and the epicenters are all in the weak variation area or its edge zone. According to the meta-instable theory, 9 of the 10 moderate-strong earthquakes occurred in the study area, which has a good correspondence with each stage of meta-instable theory. Among them, Ninglang MS5.7 and Kangding MS6.3 earthquakes all occurred at the overlap area of weak variation regions for two consecutive periods before the earthquake. Therefore, for the prediction of moderate-strong earthquakes, we should pay more attention to the overlap area of weak variation regions of horizontal vector of lithospheric magnetic field for consecutive multiple periods. From 2011 to 2013, the horizontal vector anomaly in the overlap area of Longmenshan fault zone and Xianshuihe fault zone are obvious. The analysis of the relationship between regional stress field and magnetic anomaly shows that the rupture areas of Lushan MS7.0 and Kangding MS6.3 earthquakes are affected by the stress from the northeast.
ZHANG Yu,CHEN Shuanggui,MA Huiyuan et al. Variation Characteristics of Horizontal Vector Anomaly of Lithospheric Magnetic Field in Sichuan from 2010 to 2014 Based on Meta-Instable Theory[J]. jgg, 2023, 43(7): 734-739.
