Regionalization of the Recent Tectonic Stress Field in China and Adjacent Regions

According to the stress state and force source character, the recent tectonic stress field of China and adjacent regions is classified into four classes: The first order tectonic stress district is mostly controlled by the geometry of plate boundary and the force acting on plate boundary, the stress action of this stress field shows uniformity and stability in large areas and long time. The stress action of second order tectonic stress district shows correlation in a large area. This stress field is controlled by regional block interaction. The stress regime of the third order tectonic stress district shows comparability in finite areas. This stress filed is mostly influenced by interior block interaction inside the areas. The stress character (direction, intensity, regime, etc) of the forth order stress district shows better coherence. This stress filed is mostly controlled by block and fault interaction, and some may be influenced by its crust structure and tectonic environment. Recent tectonic stress field in China and adjacent region is divided into two first order districts, four second order districts, five third order districts and twenty-six fourth order districts.