Based on the study of Akio Yoshida etc,taking North China(30°～42°N,109°～125°E)as the sample area to study the relationship between the space-time distributions of moderate and strong earthquakes in Chinese mainland.
1. The boundary between earthquakes of the Chinese mainland and industrial distribution is the line 104° (south ) - 106°E (north). To the west of this line, the level of seismicity is strong in intensity and is high in frequency, where the industrial development is relatively backward;
Theauthors have calculated the shear stress values of all the earthquakes with,m_b≥3.8 occurring inChina since 1987, and on the basis of the results, they have marked out the strong earthquake riskregions in the Chinese mainland in the next three years,giving the range of magnitudes simuta-neously.
Background of crustal movement of Chinese mainland
Based on GPS data during May 1995-March 1998 of 12 IGS stations located in the Chinese mainland and its surrounding areas, the horizontal displacement rates of these IGS stations have been determined.
The result can be available to study the background of the crustal tectonic motion in the Chinese mainland.
PWV change in the Chinese mainland in 2004 is graphed with the gridding method of splines in tension, according to the GPS data of the crust monitor observation network in China, combined with relevant meteorology information.
In order to address this issue, we must endeavor to understand more clearly the prehistoric cultures of the southeastern coast of the Chinese mainland, and especially changes in settlement and subsistence patterns.