Abstract:This paper introduces the basic principles and characteristics of Morlet wavelet transform. As an example, we take the Wenchuan earthquake, using vertical continuous waveform seismometer data from May 1-12, 2008. We then acquire the time-frequency spectrums by means of Morlet wavelet transform. According to the time-frequency spectrums, the energy amplitude of the 0.1~0.2 Hz band shows an obvious increasing trend several hours before the Wenchuan earthquake. This is a frequency anomaly caused by non-typhoon disturbances, which is well in line with existing conclusions. It is proven that Morlet wavelet transform is an effective method to analyze pre-earthquake frequency characteristics.
PI Yuyang,ZHOU Yunyao,Lu Yongqing. Application of Morlet Transform in Pre-Earthquake Data Processing of Wenchuan Earthquake Recorded by Ultra Broadband Seismograph[J]. jgg, 2018, 38(9): 974-978.