THE VARIATION OF SEISMICITY PATTERN IN NORTH CHINA

By studying the temporal-spatial distribution of seismicity in North China (34-42N, 108-124 B) it clearly shows that the transfer of the main seismic activity for different areas within different periods is quite obvious. The rift belt in front of the Taihangshan Range is one of the most important tectonic zones in this region which controls not only'the seismicity of its two ends but also that of both to the east and west of the belt. It is pointed out that since about the 19th century, seismic activity was chiefly in the east. The seismicity pattern has been evidently varied. This fact may be important in monitoring areas of future occurrences of earthquakes. It is significant for long-term earthquake prediction.