Sbox地震定位方法在洱源台阵的应用  

Application of Sbox Earthquake Location Method in Eryuan Seismic Array

作　　者：冯向东[1] 王晓山[1] 赵志远[1] 王凯英[2] FENG Xiangdong;WANG Xiaoshan;ZHAO Zhiyuan;WANG Kaiying(Hebei Earthquake Agency,Shijiazhuang 050021,China;Institute of Geology,CEA,Beijing 100029,China)

机构地区：[1]河北省地震局,石家庄050021 [2]中国地震局地质所,北京100029

出　　处：《华北地震科学》2022年第1期51-57,共7页North China Earthquake Sciences

基　　金：国家重点研发计划项目(2018YFC150330304)。

摘　　要：采用地震相对定位方法——Sbox方法,利用云南洱源亚失稳台阵、云南固定台网和临时台网的震相到时数据,对滇西北地区2018年3月18日—2020年5月21日发生的地震进行重新定位。在此基础上分析了云南漾濞M_(S)6.4地震序列的空间分布特征。结果显示,Sbox方法可显著锐化地震分布图像,增加地震丛集性,从而提高地震分布对深部构造的分辨率;漾濞M_(S)6.4地震序列与背景地震在空间分布上呈现明显的补位现象,漾濞地震属于单侧破裂,破裂方向为自北西向南东方向。在漾濞地震前几年或更长一段时期内,破裂面北西端及深部小地震发育,形成预破裂,震前在漾濞地震断层面区域形成相对地震空区,直至漾濞地震序列的发生填补了该空区。In this paper,the seismic relative location method Sbox method is used to relocate the earthquakes occurred from March 18,2018 to May 21,2020 in northwest Yunnan province based on the seismic phase reports from eryuan sub-instability station array and some Yunnan fixed stations.On this basis,the Yangbi M_(S)6.4 earthquake sequence in Yunnan province is analyzed.The results show that the Sbox method can significantly sharpen the seismic distribution image,increase the seismic clustering,and improve the resolution of seismic distribution to the deep structure.Yangbi M_(S)6.4 seismic sequence distribution and background seismic distribution have clear spatial compensating phenomenon.The rupture direction of the earthquake is from NW to SE.During a period of several years or longer before the Yangbi earthquake,small earthquakes developed at the northwest end and bottom of the rupture surface,forming a pre-rupture belt,however,in the seismic fault plane area of the Yangbi earthquake,relatively quiet area was formed before the earthquake until the Yangbi earthquake sequence filled the area.

关 键 词：漾濞M_(S)6.4地震 预破裂 深部构造分辨率 地震丛集锐化 

分 类 号：P315[天文地球—地震学]