【作者】 魏树红；

【导师】 夏雅琴；

【作者基本信息】 北京工业大学 ， 固体力学， 2006， 硕士

【摘要】 次声波观测作为北京工业大学地震研究所临震预报的重要方法之一,经过二十多年的观测和摸索,发现预测地震的震级和发震时间的有效率在80%以上。一般情况下,世界范围内7级以上地震震前都会收到次声波异常信号,异常信号结束后9天内发震,根据异常信号的幅值和时间可以预测震级和发震时间,震级误差为±0.8级,发震时间误差小于4天。但是大量的观测资料表明次声波存在多种干扰因素,如:火山爆发、冰雹、大风、雷雨、核爆炸等都产生次声波,研究这些干扰因素产生的次声波的特性,对准确的地震预测是至关重要的。将干扰信息和地震前兆信息有效地区别开来,分析和研究震前次声波信号与地震的相关性以及震前次声波信号和非地震次声波信号的特征就是本课题所要研究的内容和目的所在。为研究上述问题,本课题应用随机过程和相关性理论知识,以北京工业大学地震研究所2001年1月1日至2005年12月31日世界范围内发生的7级以上震前接收到的次声波异常信号为资料,以发生的7级以上地震为研究对象,检验次声波与地震的相关性。以2001年1月1日至2005年3月31日的太阳黑子序列与次声序列为研究对象,检验太阳黑子与次声的相关性。以1996年12月7日至2005年3月31日的太阳黑子序列与地震序列为研究对象,检验太阳黑子与地震的相关性。日本是一个地震多发的地区,本文选取5个日本地震,同时选取5个其它地区地震的次声波异常信号和5个大风、雷雨时的非地震次声波异常信号为研究对象,应用傅立叶变换和小波变换着重对震前次声波异常信号与非地震次声波信号进行频率特征分析。找出不同地区震前次声波异常信号之间、震前次声波异常信号与非地震次声波异常信号的异同。更多还原

【Abstract】 As one of important methods to forecast earthquake, we found that the infrasound observation make a good effect on the earthquake prediction by observing and researching for more than twenty years. Usually the earthquake will occur in 9 days after the abnormal infrasound signals received, we can predict the magnitude and time of the earthquake according to the time and range of signals received. The error of the earthquake magnitude is less than 0.8 and the error of the time is less than 4 days. There are abnormal infrasound signals which can be received when there is wind, thunder storm or nucleus exploded and volcano erupted. It’s very valuable for a the earthquake prediction to find the characteristic of the earthquake abnormal infrasound signals and non-earthquake abnormal infrasound signal and the correlation between the earthquake abnormal infrasound signal and earthquake by analyzing and proposing the data. What mentioned hereinbefore is the contents and significance of the paper.This paper investigated the correlations between infrasound signal before the earthquake received by the Institute of Earthquake Prediction Research in Beijing University of Technology and earthquake more than magnitude 7 occurred in the world wide from Jan. 1, 2001 to Dec. 31, 2005 by using the knowledge of random theory and correlation theory, the correlation between sunspot and infrasound from Jan.1, 2001 to Mar. 31, 2005, the correlation between sunspot and earthquake from Dec. 7, 1996 to Mar. 31, 2005.As examples, 5 earthquakes occurred in Japan, 5 earthquakes occurred in other areas and 5 non-earthquake abnormal infrasound signals received while there was wind or thunder storm were analyzed for the frequency characteristic of the signals by using Fourier transform theory. Wavelet decomposing and continuous wavelet transform of the signals were also carried out. The similarities and differences between the earthquake abnormal infrasound signals of different areas, and the similarities and differences between the earthquake abnormal infrasound signals and the non-earthquake abnormal infrasound signals were found.更多还原