用Pn-Pg走时差计算内蒙古地区地震震源深度  

Using Pg-Pn Travel-time Difference to Calculate the Focal Depth in the Inner Mongolia Area of China

作　　者：张帆[1] 徐岩[1] 宋晓燕[1] 王磊[1] 王树波[1] ZHANG Fan;XU Yan;SONG Xiao-yan;WANG Lei;WANG Shu-bo(Inner Mongolia Earthquake Agency,Hohhot 010051,China)

机构地区：[1]内蒙古自治区地震局,内蒙古呼和浩特010051

出　　处：《地震》2019年第1期81-89,共9页Earthquake

基　　金：地震监测;预测;科研三结合课题(170618);内蒙古自治区2016年度科技重大专项子课题;中国地震局地震科技星火计划(XH14012Y)

摘　　要：震源深度是地震学研究的关键参数,也是难以准确测定的参数之一。由于Pn和Pg震相的路径特征,其走时差对震源深度的变化较敏感,Pn和Pg震相是地震台网观测报告中数量较丰富且精度较高的震相数据,因此Pn-Pg方法为震源深度测定提供了简便且可行的方式。本文讨论了使用Pn-Pg走时差测定震源深度的实现方式,使用模拟数据评估了该方法的误差,结果表明,震相到时误差在一定范围时,此方法可以给出较可靠的深度结果。使用Pn和Pg走时差计算了内蒙古地区地震的震源深度,重新测定的深度频次分布更加合理,区域差异也比较明显,东部和西部的震源深度较深,中部地区震源深度较浅。The focal depth is a key parameter for seismology and one of the parameters difficult to be accurately measured.Because Pn-Pg travel time difference is sensitive to focal depth and the two phases are rich in seismic observation report with high precision,Pn-Pg method provides a simple and feasible way for focal depth determination.This paper discusses the realization of Pg-Pn method to determine focal depth.Using simulated data to evaluate the method,the results show that when phase error is in a certain range,this method can give reliable results.The focal depths of earthquakes in Inner Mongolia area were determined using this method.The results show that the remeasured depth frequency distribution is more reasonable and the regional difference is obvious.The focal depth in the east and west is deeper and the focal depth in the central region is relatively shallow.

关 键 词：震源深度 Pn—Pg时差 PTD方法 内蒙古地区 

分 类 号：P315.7[天文地球—地震学]