Determination Method of Focal Depth of Local Earthquake Using the Travel-time Difference between Pn and sPn  

作　　者：Wang Dengwei Xu Qinping Ma Fuhong Cheng Xuefen 

机构地区：[1]Xichang Seismic Center Station, Earthquake Administration of Sichuan Province, Xichang 615022, China

出　　处：《Earthquake Research in China》2011年第3期300-309,共10页中国地震研究（英文版）

基　　金：funded by the special support project;entitled "Sorting out and processing of seismic data " of central public-interest basic scientific and technological research of Institute of Crustal Dynamics;China Earthquake Administration (ZDJ2007-4)

摘　　要：In this paper,we derived the relationships between the travel time difference of sPn and Pn and the local earthquake focal depth.In these equations,the travel time difference of sPn and Pn is not related to the epicentral distance,but depends only on the regional crustal mode and the focal depth.According to the equations,we provided a simple and accurate method to determine local earthquake focal depth by using the travel time difference between phase sPn and Pn.This method has been used to determine the focal depths of two earthquake of MS6.1 and MS5.6 which occurred at the junction of Panzhihua and Huili,Sichuan on August 30 and 31,2008.The results were compared to those from other sources such as the China Earthquake Networks Center,and the comparison shows that the results are accurate and reliable.In this paper, we derived the relationships between the travel time difference of sPn and Pn and the local earthquake focal depth. In these equations, the travel time difference of sPn and Pn is not related to the epicentral distance, but depends only on the regional crustal mode and the focal depth. According to the equations, we provided a simple and accurate method to determine local earthquake focal depth by using the travel time difference between phase sPn and Pn. This method has been used to determine the focal depths of two earthquake of Ms6. 1 and Ms5.6 which occurred at the junction of Panzhihua and Huili, Sichuan on August 30 and 31, 2008. The results were compared to those from other sources such as the China Earthquake Networks Center, and the comparison shows that the results are accurate and reliable.

关 键 词：Focal depth sPn seismic phase Travel-time difference between sPn and Pn Critical epicentral distance 

分 类 号：P315.3[天文地球—地震学] P315.78[天文地球—固体地球物理学]