The Scanning Characteristics of Spatial and Temporal Dynamic Pictures of the Seismicity in the South Yellow Sea and Its Coast Region

On the basis of the viewpoint of preparation of strong earthquakes in group, the spatial and temporal scanning characteristics of the seismicity in the South Yellow Sea and its coast region are studied, and some problems regarding the prediction of seismic hazard are also discussed. The results show that the seismic activity of M = 4.0 earthquakes has overall presented a relative stable state, but the partially concentrated area which evolves and migrates and the anomalous 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 anomalous area. The accumulative frequency of M = 4.0 earthquakes in the anomalous 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 anomalous tranquil period. The spatial and temporal uneven phenomenon of seismicity has some stability and reproducibility, and has some practical importance for the seismic hazard prediction of the intermediate-term to intermediate- and short-term and reduction of the risk area.