2010年2月27日智利地震地球球型自由振荡研究

The Study of Spheroidal Mode of the Earth Free Oscillation Excited by the Chile Earthquake on Feb.27,2010

利用中国数字地震台网(CDSN)5个台站的波形资料,采用功率谱密度估计方法,提取了智利地震激发的地球球型自由振荡,并与地球初步参考模型(PREM)的理论自由振荡周期进行对比,发现球型振荡振型周期与地球初步参考模型预测的球型自由振荡周期基本吻合。所得结果可以进一步用来研究地震震源机制和地球内部结构,并对大地震的震源破裂分布给出一定的约束。

Based on waveform data recorded by 5 stations of China Digital Seismic Network（CDSN）,using the power spectral density（PSD） estimation method,we extracted spheroidal mode of the earth free oscillation excited by the Chile earthquake.They are consistent and nearly same with the frequencies of the modes of Preliminary Reference Earth Model（PREM）.The results can be further used to study the focal mechanism and the Earth＇s interior structure,and give certain constraints on the big earthquake rupture distribution.