震相,是介质结构与震源运动信息在地震图上的总体现。由地震图研究介质结构状况,是传统地震学的基本任务。但是,由地震图研究震源运动状况,确是现代地震学一项很重要的内容。在这方面,人们比较多地利用P波初动所提供的震源信息,研究震源性质,例如初动半周期法、初动频谱法、初动波形拟合法、初动幅度及初动方向求解断层面的方法等。 The seismic phase is the general manifestation of the media structure and the motion information of the source on the seismogram. Seismogram to study the structure of the medium structure is the basic task of traditional seismology. However, the study of seismogenic motions by seismograms is indeed a very important aspect of modern seismology. In this regard, people make more use of the source information provided by the initial P-wave to study source properties such as the first half-cycle method, the first-run spectrum method, the first-time waveform fitting method, the initial amplitude and the initial direction Level method and so on.