临汾盆地及邻区地震重定位和b值研究  

Study on Seismic Relocation and b-value in the Linfen Basin,Shanxi Province and its Surrounding Areas

作　　者：张聪聪[1,2] 张英杰[3] ZHANG Cong-cong;ZHANG Ying-jie(Linfen Earthquake Monitoring Center Station,Shanxi Earthquake Agency,Linfen,Shanxi 041000,China;National Continental Rift Valley Dynamics Observatory of Taiyuan,Taiyuan,Shanxi 030025,China;Handan Earthquake Monitoring Center Station,Hebei Earthquake Agency,Handan,Hebei 056000,China)

机构地区：[1]山西省地震局临汾地震监测中心站,山西临汾041000 [2]太原大陆裂谷动力学国家野外科学观测研究站,山西太原030025 [3]河北省地震局邯郸地震监测中心站,河北邯郸056000

出　　处：《山西地震》2023年第2期5-10,共6页Earthquake Research in Shanxi

基　　金：山西省地震局科研项目(SBK-2214),中国地震局地质研究所国家野外科学观测研究站项目(NORSTY20-12)。

摘　　要：选取2010年-2020年地震台网记录的震相数据,采用双差定位法对临汾盆地及邻区中小地震进行重定位,并对研究区域进行b值空间扫描。结果表明,临汾盆地及邻区具有明显的两个优势地层发震层,深度分别为4~10 km和18~24 km,地震多数集中于较深的发震层附近;贯穿太原盆地、灵石隆起和临汾盆地存在一条呈“S”状的地震条带,在临汾盆地北端的地震条带清晰且发生北西向转折,在灵石隆起西侧可能存在深层地震破碎带或隐伏断裂;在临汾盆地洪洞凹陷和辛置凸起下方存在一个地震空区;临汾盆地洪洞凹陷及周边处于低应力异常区,该区域地震密集成簇,是1303年洪洞8.0级地震的震后应力构造调整区;鄂尔多斯块体的逆时针转动和灵石隆起的阻挡作用,造成灵石隆起与临汾盆地交界处容易积累应力,地震频发。In this study,seismic phase data recorded by the seismic network from 2009 to 2020 are utilized to perform seismic relocation and b-value analysis for small to moderate earthquakes in the Linfen Basin and its neighboring regions.The results show that the study area exhibits two distinct seismogenic layers at depths of 4-10 km and 18-24 km,with seismicity mainly concentrated near the deeper seismogenic layer.A seismic belt with an"S"shape is observed,extending through the Taiyuan Basin,Lingshi Uplift,and Linfen Basin.The northern part of the Linfen Basin shows a clear northwestward bending of the seismic belt,while a deep seismic rupture zone or concealed fault may exist on the western side of the Lingshi Uplift.A seismic gap is identified beneath the Hongdong Depression and Xinzhi Uplift.The Hongdong Depression and its surrounding areas are characterized by low stress anomalies,where seismicity is clustered,representing a post-seismic stress adjustment zone following the 1303 M8 earthquake.The counterclockwise rotation of the Ordos Block and the blocking effect of the Lingshi Uplift result in stress accumulation at the junction between the Lingshi Uplift and the Linfen Basin,leading to frequent earthquakes in this region.

关 键 词：B值 地震条带 临汾盆地 双差定位 

分 类 号：P315.61[天文地球—地震学]