震源硬化模型的理论、实验及观测事实依据

从前兆异常共性特征、有关理论分析及岩石实验结果等方面,论证了震源硬化模型的科学性和合理性。

Evidence of theory, test and observation for source hardening model

From the results of precursory generality, relevant theoretical analysis and rock test, the science and reasonableness of the source-hardening model are discussed in this paper. It is pointed out that the source of strong earthquake experiences four stages of elastic deformation, media hardening, fracturing nucleation and in stabilizing.The distur- bance range of source stress and strain is only half of the source size, which can not affect several hundred km away, but at least 500 km for precursory anomaly before a M7 earth- quake. Therefore, the precursory anomalies and earthquakes are all the results and expressions of action of regional stress fields. The precursory anomalies are the results of fissure, deformation and displacement generating from shallow rock body around the observational points. The earthquakes are the results of quick fracture of rocks around the source areas. Their occurrences in the same field are not the reciprocal causation. The hardening of media around source is the main cause generating quiescence of moderate and small shocks within the source areas in the medium and short stages t non precursory anomaly, seismic gaps, as well as precursory anomaly migrating from periphery to the center.