Earth's Free Toroidal Oscillations Observed by the JCZ-1 Seismometer  

作　　者：Wu Haibo Hu Hong Zhang Nian 

机构地区：[1]Earthquake Administration of Hubei Province

出　　处：《Earthquake Research in China》2013年第2期165-177,共13页中国地震研究（英文版）

基　　金：sponsored by the Key Program of National Natural Science Foundation of China ( 40730317)

摘　　要：We firstly detected the Earth's free toroidal oscillations excited by three large earthquakes in Japan,2011,Chile,2010 and Indonesia,2005 from the observed data of the JCZ-1 seismometer at Wuhan Seismic Station. The eigenperiods of basic modes (0T2 - 0T67 ) and first modes (1T2 ～ 1T50 ) were detected,and their error ratios were less than 0. 5% by comparing the observed eigenvalues with the theoretical eigenvalues in PREM. We supplemented some modes- 0T11,0T15 , 0T19 , 1T4 , 1T5 and 1T14 ,which were not mentioned in PREM,and also observed the spectral line multi-peak phenomenon from 0T2, 0T6 , 0T7 and 0T8 . These results show that the JCZ-1 seismometer is able to precisely observe the Earth's long period toroidal free oscillations.We firstly detected the Earth＇s free toroidal oscillations excited by three large earthquakes in Japan,2011,Chile,2010 and Indonesia,2005 from the observed data of the JCZ-1 seismometer at Wuhan Seismic Station. The eigenperiods of basic modes （0T2 - 0T67 ） and first modes （1T2 ～ 1T50 ） were detected,and their error ratios were less than 0. 5% by comparing the observed eigenvalues with the theoretical eigenvalues in PREM. We supplemented some modes- 0T11,0T15 , 0T19 , 1T4 , 1T5 and 1T14 ,which were not mentioned in PREM,and also observed the spectral line multi-peak phenomenon from 0T2, 0T6 , 0T7 and 0T8 . These results show that the JCZ-1 seismometer is able to precisely observe the Earth＇s long period toroidal free oscillations.

关 键 词：Earth＇s toroidal free oscillations  JCZ-1 seismometer  Power spectral density  Mode 

分 类 号：P315.6[天文地球—地震学]