南黄海及沿岸地震活动时空动态扫描特征

The Scan Characteristics of Spatial and Temporal Dynamic Picture of the Seismicity in the South Yellow Sea and Its Coast

从中强震成组孕育出发,研究了南黄海及沿岸地区地震活动时空动态图象扫描特征,探索了该区地震危险性预测的有关问题。结果表明,该区20多年来4级地震活动总体上呈相对平稳状态,但在不同时段则出现不断演变迁移的4级地震局部集中区及低b值区等异常区域,5～6级中强地震大都发生于异常区的边缘或附近;异常区内4级地震累积频度往往呈非线性指数加速,中强震发生于4级地震非线性指数加速的后期或其后的异常平静期中。这种地震活动时空非均匀现象具有一定的稳定性和重现性,对于中期至中短期地震危险性预测及缩小危险区范围具有一定的实用意义。

From the viewpoint of impending of strong earthquake groups, the scan characteristics of spatial and temporal dynamic picture of the seismicity in the South Yellow Sea and its coast are studied, and some problems about the prediction of seismic hazard are also discussed. The results show that the seismic activity of M =4 0 earthquake has overall presented a relative stable state, but the partial concentrated area which evolutes and migrates and the abnormal low b \|value area have appeared in different periods, and the moderately strong earthquakes with M =5 0～6 0 have taken place on the edge of the abnormal area. The accumulative frequency of M =4 0 earthquakes in the abnormal area presents non\|linear index acceleration and the moderately strong earthquakes have appeared in the late period of the non\|linear index acceleration of M =4 0 earthquakes or in the later abnormal calm period. The spatial and temporal noneven phenomenon of seismicity have some stability and reproducibility, and have some practical importance for the seismic hazard prediction of intermediate term to intermediate\|short term and for the reduction of the hazard area.