Preliminary Study on the Horizontal Crustal Deformation in Chinese Continent

In the paper, the current strain field and stress field in Chinese continent have been discussed based on the processed data from two GPS campaigns of national GPS network carried out in the years of 1994 and 1996. With a principal compressional strain direction of NNE, the western and eastern parts of Qinghai-Xizang subplate are dominated by extensional strain and the central part by compressional strain. Along the southwestern segment of southeastern part of Qinghai-Xizang subplate, i.e. Yunnan area, the principal compressional strain direction is NW and the compressional strain is equivalent to the extensional strain in magnitude. The principal compressional strain of Xinjiang subplate is mainly NNE and NE with a difference in the strain magnitude. The principal compressional strain in North China subplate is quite effective in NE and nearly EW directions with differences along some segments. However, the compressional strain is corresponding to the extensional strain in magnitude in most areas. The principal compressional strain directions of South China subplate are NNW and NW, and in the direction perpendicular to it, the horizontal strain decreased significantly. At present, the compressional strain in South China subplate is superior. The integral principal compressional strain in the crust of Chinese continent trends to NNE and NE, which has just reflected the principal stress direction of crustal activity in the present stage.