Detection of spheriodal free oscillation excited by Peru 8.2 M_(s) earthquake with five international superconducting gravimeter data  

作　　者：LEI Xiang'e XU Houze SUN Heping 

机构地区：[1]Key Laboratory of Dynamic Geodesy, Institute of Geodesy and Geophysics. Chinese Academy of Sciences, Wuhan 430077, China Key Laboratory of Dynamic Geodesy, Institute of Geodesy and Geophysics. Chinese Academy of Sciences, Wuhan 430077, China Key Laboratory of Dynamic Geodesy, Institute of Geodesy and Geophysics. Chinese Academy of Sciences, Wuhan 430077, China

出　　处：《Science China Earth Sciences》2005年第1期123-133,共11页中国科学（地球科学英文版）

基　　金：the Key Project of theKnowledge Innovationand the Hundred Talents Pragram,Chinese Academy of Sciences(Grant No.KZCX3-SW-131);the National Natural Science Foundation of China(Grant No.40074018,40374029).

摘　　要：In this paper, authors obtain the spectral peaks of the earth free oscillation and check all normal modes from 0S0 to 0S48 accurately, with the Fourier analysis and the maximum entropy spectrum method dealing jointly with six groups of the observational residual data from five international superconducting gravimeter stations. By comparing the observational results in this paper with three former groups of observations or models, authors notice an extra discrepancy between two observational 0S2 modes excited separately by Peru earthquake and Alaska earthquake, which probably mirrors the anisotropy of the Earth's inner core. The analysis on the splitting 1S2 mode shows that the asymmetric factor of rotationwise spectral splitting is possible to be different from that of anti-rotationwise spectral splitting.In this paper, authors obtain the spectral peaks of the earth free oscillation and check all normal modes from 0S0 to 0S48 accurately, with the Fourier analysis and the maximum entropy spectrum method dealing jointly with six groups of the observational residual data from five international superconducting gravimeter stations. By comparing the observational results in this paper with three former groups of observations or models, authors notice an extra discrepancy between two observational 0S2 modes excited separately by Peru earthquake and Alaska earthquake, which probably mirrors the anisotropy of the Earth's inner core. The analysis on the splitting 1S2 mode shows that the asymmetric factor of rotationwise spectral splitting is possible to be different from that of anti-rotationwise spectral splitting.

关 键 词：8.2 Ms Peru earthquake  DETECTION of EARTH free oscillation  observation of SUPERCONDUCTING gravimeter anisotropy of earth's INNER core. 

分 类 号：N[自然科学总论]