Precise Location of Earthquakes at the Eastern Boundaries of the Sichuan-Yunnan Rhombic Block

作者：Fu Ying,Hu Bin,Long Feng,Wang Shiyuan

摘要：Based on the seismic station data sets from Sichuan and Yunnan provinces,we employed a multi-step seismic location method(Hypo2000+Velest+HypoDD)to precisely locate the 7,787 earthquakes that occurred during 2010-2015 along the eastern boundaries of the Sichuan-Yunnan rhombic block,namely from southern Dawu to the Qiaojia segment.The final results show that location precision is greatly advanced and epicenter distribution exhibits good consistency with the linear distribution of the seismic faults.Earthquake distribution is quite intensive at the intersection region in the southern segment of the Xianshuihe fault,the Anninghe fault zone,the Xiaojinhe fault zone and the Daliangshan fault zone to the east.The depth profile of seismicity shows a clear stepwise activity along the active seismic fault zones.The profile crossing the faults of the Xianshuihe,Anninghe,and Daliangshan presents a complex interaction among faults near the multiple faults intersection region,Shimian,where the earthquakes are obviously divided into two groups in depth.Earthquakes are very rare at the depth of 15km-20km,which is consistent with the region of the plastic rheology between 14km-19km calculated by Zhu Ailan et al.,(2005).

发文机构：Sichuan Earthquake Agency

关键词：EASTERNboundariesofSichuan-YunnanrhombicBLOCKPRECISELOCATIONHypo2000HypoDD

分类号： P[天文地球]