Studies on the difference of rock medium properties in north China and southeast China coastal areas.
华北与东南沿海地区岩石介质差异性研究

The differences, in this paper, of the rock medium properties in north China and southeast China coastal areas are studied by seismicity method. The ap parent stress drop and ambient stress values of seismic activities in areas ment ioned above are also calculated. The quantitative characteristics for their diff erences are described by using fractal theory. The results showed that the ambie nt stress values obviously experiense fluctuations in north China (Haicheng of T angshang) areas, but does not change obviously in southeast China coastal (Fuji an) areas. It reveals that the rock medium features are different between the n orth China and south east China coastal areas. And it means that the dynamic characteristics under the control by the plate structure in areas mentioned above are different, espe cially, the rock properties of the thin crust possibly depend on the depth.Finally, the complexity of variation in three areas is discussed based on the po int of dynamic view. In the meantime, problems possibly existing are also discu ssed.