山西分区地壳速度模型的建立及应用  

Establishment and Application of Regional Crustal Velocity Model in Shanxi Zone

作　　者：张蕙[1] 朱元清[2] 宋秀琴 殷伟伟[1] ZHANG Hui;ZHU Yuanqing;SONG Xiuqin;YIN Weiwei(Shanxi Earthquake Agency,69 Second Section of Jinci Road,Taiyuan 030021,China;Shanghai Earthquake Agency,87 Lanxi Road,Shanghai 200062,China)

机构地区：[1]山西省地震局,太原市030021 [2]上海市地震局,上海市200062

出　　处：《大地测量与地球动力学》2021年第5期448-453,共6页Journal of Geodesy and Geodynamics

基　　金：山西省科技厅青年基金(201801D221044);山西省地震局项目(SBK-2034,SBK-2023,SBK-1922)。

摘　　要：将山西地区划分为北部、中部和南部3个区域,利用2009~2019年山西省及周边50 km范围内的地震事件波形资料,使用线性拟合、折合走时及Hyposat批量定位等方法确定各分区的地壳速度模型。采用批量定位比较残差、PTD方法测定震源深度及非天然地震事件检验等方法对分区模型进行验证,结果显示,相对山西2015速度模型,分区模型的适用性更佳,两者的差别主要体现在P波在上地壳和莫霍面的传播速度及莫霍面深度方面。分区模型显示,P波在上地壳的传播速度由北向南逐渐变小,而在莫霍面的速度则逐渐变大,莫霍面深度表现为北厚南薄。北部区域上地壳速度偏高,莫霍面速度偏低,地壳厚度较厚,可能是受大同火山的影响;南部区域上地壳速度偏低,推测是由于巨厚沉积层所致。In this study,the Shanxi area is divided into three areas of north,middle and south,using seismic event waveform data in and around 50 km in Shanxi province from 2009 to 2019,using linear fitting,reduced travel time,and Hyposat batch processing methods.The crustal velocity models of each subarea are determined,and three methods are used to verify the subarea model:batch positioning to compare residuals,PTD method to determine the source depth,and unnatural seismic events.The results show that the zoning model has better applicability to the Shanxi 2015 velocity model.The difference between the zoning model and the Shanxi 2015 velocity model is mainly reflected in the propagation velocity of the P-wave in the upper crust and Moho and the depth of the Moho.The zoning model shows that the propagation velocity of the crust gradually decreases from north to south,while the velocity of the Moho surface gradually increases,and the depth of the Moho shows a trend of thick north and thin south.The upper crust velocity value is higher due to the Datong volcano in the northern region,while the lower crust and Moho velocity are lower,and the crust thickness is thicker.The upper crustal velocity of southern region is lower,due to the existence of huge thick sediments.

关 键 词：地壳速度模型 山西地区 非天然地震 大同火山 

分 类 号：P313[天文地球—固体地球物理学] P315[天文地球—地球物理学]