小波分析方法在钻孔应变数字化资料处理中的应用

Application of Wavelet Analysis Method in Digital Data Processing of Borehole Strain

基于小波变换理论,提出应用小波变换的分析方法来识别和分离不同频率信息、提取地震趋势异常和短临异常。研究表明,利用小波变化可以较容易地识别和剔除佘山台钻孔应变的地震干扰、气压干扰、仪器故障干扰等影响钻孔应变观测资料精度的诸多干扰。利用小波变换方法对面应变日均值进行分析,发现在海域大震前,小波变换第三阶细节部分在震前出现持续数月以上的高频脉冲,且面应变有鼓包现象。

Based on the theory of wavelet transform,the analysis method of wavelet transform is proposed to identify and separate different frequency information,extract seismic trend anomalies and short-impending anomalies.The results show that the seismic interference,air pressure interference and instrument fault interference which affect the accuracy of borehole strain observation data can be easily identified and eliminated by using wavelet transform.The daily mean of surface strain is analyzed by using wavelet transform method.It is found that before a large earthquake in the sea area,the third order detail of wavelet transform appears high frequency pulses lasting for more than several months before the earthquake,and the surface strain is bulging.