组合震源模式的数值模拟研究

针对随机介质模型和组合震源模型，应用二维网络系统有限元数值模拟方法，研究了微震的空间和时间分布序列及震级－频度关系。结果表明，微震从起初随机无序的空间分布状态逐渐向临震前主震源区域集中，呈现有序分布迁移，前兆具有“先外围，后震中”的传播特征。此外，震级－频度的线性关系只近似存在于中等震级范围内，对于高震级与低震级都有很大的偏移

STUDY OF NUMERICAL SIMULATION ON COMBINATION PATTERN OF AN EARTHQUAKE SOURCE

Based on the model of stochastic medium and the model of composite focus,the spatial distribution and time sequence of microquakes and the magnitude frequency correlation were discussed by using finite element numerical simulation in this paper.The results show that the disorder of the spatial distribution of microquakes in initial stage was translated to the order in main shock stage.The precursors are characterized by the propagation from periphery to center.In addition,the linear relation between magnitude and frequency only exists in the middle magnitude range and very large deviation exists in the high and low magnitude ranges.