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摘要
Anomalous infrasound waves were received by five infrasonic monitoring stations four days before a small-magnitude earthquake which happened on 12 October 2011. Waveforms of these five signals are consistent, which are "N" impulse waves with same duration of about one hour. Based on the Wigner-Ville distribution method, time-frequency analysis of the signals suggests that waves' energies concentrate mainly below the frequency of 0.025 Hz. Correlation coefficients between two signals are all up to about 0.8. The infrasonic source is imaged and located by the method of beamforming, and the results show that distance between the source and epicenter is about 5 km. Study of this paper proves that low-frequency atmospheric infrasonic waves may appear before earthquakes, so valuable information could be obtained by studying this kind of infrasonic waves.
- 出版日期2012-10
- 单位中国科学院声学研究所
