JCZ-1型地震仪观测的地球环型自由振荡

Abstract

Abstract: We first studied Earth's free torsional oscillation using observed data of JCZ-1 seismometer. JCZ-1 seismometer at the Wuhan Observation Station has observed the Earth's free oscillations excited by the great 2011 Japan earthquake, the great 2010 Chile earthquake and the great 2005 Indonesia earthquake, we detected the eigen periods of basic and first mode: ₀T₂~₀T₆₇ and ₁T₂~₁T₅₀, and error ratio is less than 0.5% by comparing with the PREM theoretical eigenvalues. We also complemented some modes: ₀T₁₁, ₀T₁₅, ₀T₁₉, ₁T₄, ₁T₅, ₁T₁₄, which are not mentioned in PREM, and observed the multi-peak phenomenon of ₀T₂, ₀T₆, ₀T₇ 和₀T₈. The results show that JCZ-1 seismometer can precisely observe ultralow frequency and long period free oscillations of the Earth.

Key words: Free torional oscillations of the Earth, JCZ-1 seismometer, Power spectral density, Oscillation modes

CLC Number:

P315

WU Hai-bo, HU Hong, ZHUANG Nian. Free Torsional Oscillations of the Earth Observed by the JCZ-1 Seismometer[J]. EARTHQUAKE, 2012, 32(3): 15-27.

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Free Torsional Oscillations of the Earth Observed by the JCZ-1 Seismometer

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