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 epicen...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.展开更多
On March 13,2007,two earthquakes with M4.7 and M4.6 occurred in Zhengfang Village,Shunchang,Fujian.The M4.7 earthquake is the most intensive one in the Fujian region since the establishment of the Fujian digital seism...On March 13,2007,two earthquakes with M4.7 and M4.6 occurred in Zhengfang Village,Shunchang,Fujian.The M4.7 earthquake is the most intensive one in the Fujian region since the establishment of the Fujian digital seismic networks.These two earthquakes provide us with valuable first-hand observation data for seismological research.This paper analyzes their wave-forms and concludes that(1)the crustal thickness in the seismic region is estimated to be about 40km according to the observed head-wave critical distance;(2)there is a salient difference between the ratios of S-wave's maximum amplitudes of these two earthquakes;(3)the focal depth of the M4.7 earthquake is estimated to be 8.4km according to the clear depth phrase sPn in waveforms,which is the same with the result of other determination methods.展开更多
基金funded by the special support projectentitled "Sorting out and processing of seismic data " of central public-interest basic scientific and technological research of Institute of Crustal DynamicsChina Earthquake Administration (ZDJ2007-4)
文摘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.
基金sponsored by the Joint Earthquake Science Foundation of China (106094)
文摘On March 13,2007,two earthquakes with M4.7 and M4.6 occurred in Zhengfang Village,Shunchang,Fujian.The M4.7 earthquake is the most intensive one in the Fujian region since the establishment of the Fujian digital seismic networks.These two earthquakes provide us with valuable first-hand observation data for seismological research.This paper analyzes their wave-forms and concludes that(1)the crustal thickness in the seismic region is estimated to be about 40km according to the observed head-wave critical distance;(2)there is a salient difference between the ratios of S-wave's maximum amplitudes of these two earthquakes;(3)the focal depth of the M4.7 earthquake is estimated to be 8.4km according to the clear depth phrase sPn in waveforms,which is the same with the result of other determination methods.
