地脉动在系舟山北麓断裂次级断裂探测中的应用  

Application of microtremors to detect the secondary faults of the northern piedmont fault of Xizhou Mountain

作　　者：闫小兵[1] 梁瑞平 王伟君[3] 郝雪景 YAN Xiaobing;LIANG Ruiping;WANG Weijun;HAO Xuejing(Shanxi Earthquake Agency,Taiyuan 030002,Shanxi,China;Xinzhou Housing and Urban-Rural Development Bureau,Xinzhou 034001,Shanxi,China;Institute of Earthquake Forecasting,CEA,Beijing 100036,China)

机构地区：[1]山西省地震局,山西太原030002 [2]忻州市住房和建设局,山西忻州034001 [3]中国地震局地震预测研究所,北京100036

出　　处：《地震工程学报》2023年第2期421-430,共10页China Earthquake Engineering Journal

基　　金：山西太原大陆裂谷动力学野外站计划项目(NORSTY20-05);中国地震局地震预测研究所基本科研业务专项(2017IES0101);忻州市区活动断层探测与地震危险性评价(XZHDC-01)。

摘　　要：系舟山北麓断裂为1038年定襄71/4级地震的发震构造,在盆地内部可能存在一条或多条次级断裂,并有可能非常邻近忻州城区,使用地脉动方法对系舟山北麓断裂是否存在次级隐伏断裂进行探测。通过共振频率的横向变化以及基岩深度和频率的关系获得了约17个比较显著的断点位置,指示出系舟山山前存在三条比较显著的次级断裂,以及它们的断点位置、相对错距和相应的走向分布,为忻州市区防震减灾提供基础资料。The northern piedmont fault of Xizhou Mountain is the seismogenic structure of the Dingxiang M 71/4 earthquake in 1038.It may have one or more secondary faults in the basin,which may be very near Xinzhou city.This study uses the microtremor method to detect whether hidden secondary faults exist in the northern piedmont fault of Xizhou Mountain.The locations of approximately 17 remarkable breakpoints were obtained through the lateral change in resonance frequency and the relationship between bedrock depth and frequency.The results indicate that three obvious secondary faults exist in front of Xizhou Mountain,as well as the location of their breakpoints,relative offset,and corresponding strike distribution.This research provides basic data for earthquake prevention and disaster reduction in Xinzhou city.

关 键 词：系舟山北麓断裂 地脉动 地脉动水平向与垂直向谱比 

分 类 号：P315[天文地球—地震学]