The Deformation Characteristic Of The Northeastern Marginof Qinghai-Tibet Plateau Constrained By GPS Observations

The northeastern margin of the Qinghai-Tibetan Plateau is the front position of the whole plateau, and it is also the region in which the tectonic movement is intense, and the earthquake is strong. This area has many advantages in the aspects of tectonic activity, geographical location, natural environment, Therefore, with the help of geodetic instruments to study the use of these advantages within the margin of the Qinghai-Tibet Plateau northeast crustal deformation problem, is a very meaningful research. Especially with the development of GPS technique, it is widely used in the study of crustal movement, Many obeservations and researches have been done by lots of departmets in this area. As one of them,"Crustal Movement Observation Network of China", has about 143 GPS stations with two periodic observation data(1999,2001).All of these data are good support to inverse and acquire the stress and strain or tectonic activity of the region. Therefore, the author demarcates this area based on GPS observational data as well as geological structure features and activities of the main fault. Then the rotation and strain parameters of each block are estimated by respectively applying ellipsoid model, sphere model, the integral rotation and linear strain activity block model. It is also analyzed the basic characteristics of strain field of this area. At the same time as bound for GPS displacement data, the author studied the horizontal deformation characteristics by using the finite element method in the region, and has done some preliminary study in the dynamic mechanism of crustal deformation causes of the northeastern margin of the Qinghai-Tibet Plateau. By comparing the two methods, the author concludes that they have certain advantages in the study of block deformation and good consistency in the research on the spatial distribution of regional deformation characteristics of high-value areas. Another paper also discussed the characteristics of crustal stress and strain the relationship between seismic activity.