发展预测地震危险性的定量方法不仅要求发展地震孕育机制的理论,同时要求发展有关的预报观测方法。目前广泛使用的预报征兆之一是P波走时的变化,波速比V_P/V_S的变化以及与其相关的其他特征标志的变化。在理论上波速变化是以震源处介质的宏观弹性变化为依据的。从实际观点来看这种观测是合算的,因为它可在现有台网地区进行,并且不要求额外的消耗。广泛的使用这种方法,要求对它的各个方面仔细分析研究。本文对震源区地震 The development of quantitative methods for predicting seismic hazards not only requires the development of theories of earthquake breeding mechanisms, but also calls for the development of relevant forecasting methods. One of the most widely used prognostic indicators is the change of P wave travel time, the change of wave velocity ratio V_P / V_S and other characteristic signs related to it. In theory, the change of wave velocity is based on the macroelastic change of the media at the source. This observation is cost-effective from a practical point of view as it can be done in the existing network area and does not require additional consumption. The widespread use of this method requires careful analysis of all aspects of it. This article focuses on the earthquake in the source area