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本文从理论上与实际资料分析上入手,较系统而广泛地研究了强震及中强震前地震波的动力学特性。首先,选取多相介质模型来模拟乎震区的舍裂隙岩石。在两相介质情况下用传波理论研究了地震波动力学特性,如振幅和皮形的一般变化。所得的理论结果表明,P波、S波、面波及尾波等的振幅、振动特续时间,周期或频谱等在大震前均可能出现某些前兆异常变化。其次,借助于观测资料,本文介绍了探索地震波动力学特性前兆异常的一些有效处理方法。特别使用了对尾波和短周期瑞雷波的前兆异常的分析处理方法。除天然小震资料外,还使用了矿山人工爆破资料。作为例子,本文得到了在溧阳台(距M=6.0震中22公里),天平山台(Δ=190公里)和杭州台(Δ=220公里)从马鞍山铁矿爆破源(震中西北86公里)爆破中记到的直达波和反射波的新的资料结果,从中较详细地研究了P波和S波的振幅、振幅比、初动周期偏差和尾波的某些特性(相对走时,频率变化,振幅衰减及由尾波确定的Q值)。然后,本文利用大量的实际观测资料,具体剖析和研究了我国唐山(M=7.8)、海城(M=7.3)、松潘(M=7.2)、溧阳(M=6.0)及其它一些强震和中强震前的P波、S波、短周期而波和尾波的多种动力学特性(振幅、振幅比,初动周期偏差,波形和频谱,振动持续时间等)出现的前兆异常变化,在此基础上,初步归纳了地震波动力学特性前兆异常变化时空分布的一般特点,並与波速异常加以对比。最后,对所得的结果及其在地震预报中的应用作了简要的讨论。这里要着重指出的是,大震前地震波的某些动力学特性的前兆变化能明显地观测到。因此,如果同时使用地震波的运动学和动力学特性,我们就能得到更多的地震前兆信息。
This paper starts from the theoretical and practical data analysis, and systematically and extensively studies the dynamic characteristics of the seismic waves before and after the strong earthquakes. First, the multiphase medium model is chosen to simulate Shear Rocks in the Earthquakes. Under the condition of two-phase medium, the wave dynamics is studied by the theory of propagating wave, such as the general variation of amplitude and skin shape. The theoretical results obtained show that some precursory anomalies may occur before large earthquakes, such as the amplitude of P waves, S waves, surface waves and coda waves, the duration of special vibrations, periods, or spectra. Secondly, with the aid of observation data, this paper introduces some effective methods to explore precursory anomalies of seismic wave dynamics. In particular, the analysis of precursor anomalies to coda and short-period Rayleigh waves is used. In addition to the natural small earthquake data, but also the use of mine artificial blasting data. As an example, this paper obtained the blasting results from Ma’anshan iron ore blasting source (86 km northwest of epicenter) on Liyang platform (22 km away from epicenter of M = 6.0), Pingdingshan station (Δ = 190 km) and Hangzhou station (Δ = 220 km) In this paper, we study in detail the amplitude and amplitude ratio of P-wave and S-wave, the deviation of initial period and some characteristics of coda wave (relative travel time and frequency change, Amplitude attenuation and Q value determined by the wake wave). Then, based on a large amount of actual observation data, this paper analyzes and studies Tangshan (M = 7.8), Haicheng (M = 7.3), Songpan (M = 7.2), Liyang (M = 6.0) and other strong earthquakes A variety of dynamic characteristics (amplitude, amplitude ratio, initial period deviation, waveform and frequency spectrum, duration of vibration, etc.) of P-wave, S-wave and short- On this basis, the general characteristics of spatio-temporal distribution of precursory anomalous changes of seismic wave dynamics characteristics are initially summarized and compared with the anomalous wave velocity. Finally, the results of the study and its application in earthquake prediction are briefly discussed. It is important to note here that precursory changes in some of the dynamic characteristics of the seismic wave before the major earthquake can be clearly observed. Therefore, if both the kinematics and dynamics of seismic waves are used, we can get more information about earthquake precursors.