Study on the potential strong-earthquake risk for the eastern boundary of the Sichuan-Yunnan active faulted-block, China
川滇活动地块东边界强震危险性研究

Taken the eastern boundary of the Sichuan-Yunnan active faulted-block in southwestern China as an example,spatial stress distribution and potential strong-earthquake risk have been studied based on detailed b value calculation from seismic data of the last 31 years.The main results show:(1) The spatial distribution of b values displays significant heterogeneity for various faults and fault-segments of the eastern boundary of the Sichuan-Yunnan active faulted-block,which reflects the spatial difference of cumulative stress level along the boundary fault zones.(2) There are several asperities,one located at Songming on Xiaojiang main fault,one between Qiaojia and Dongchuan,and one at northwestern Songming near the main fault,two near Mianning on Anninghe fault and near Xichang on Zemuhe fault,and a large-scale one from Daofu to Qianning on central-southern portion of the Xianshuihe fault.The asperities may be the potential seismogenic sources of large or strong earthquakes along the eastern-boundary in the near future.