The Earth’s Free Spherical Oscillations of the Great Japan Earthquake

Abstract:

An M9.0 earthquake struck Japan on March 11, 2011 and the strong earthquake made continuous oscillation of the Earth. We first studied the Earth’s free oscillations using observations of VHZ channel of China Digital Seismic Network (CDSN). Since the frequency response of seismograph in CDSN suppresses the information of low frequency signal, we do not need to remove the solid tide in our data processing. We extracted 72 clear spherical modes of (₀S₀, ₀S₂ to ₀S₇₂) of the Earth’s free oscillation and 21 harmonic modes and they are consistent and nearly same with the frequencies of the modes of Preliminary Reference Earth Model (PREM). Spectral splitting phenomenon is observed obviously in ₀S₂, ₀S₃, ₀S₄ and ₁S₂ free oscillation modes.

• Periodical: Advanced Materials Research (Volumes 622-623)
• Pages: 1664-1669
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.622-623.1664
• Online since: December 2012
• Authors: Ye Wu, Yong Ge Wan, Liang Ding
• Keywords: Free Oscillation Mode, Power Spectral Density Estimation, Spectral Splitting

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