Study On The Chamcterisucs Of Crust Motion In North China By GPS Data

North China is in the east part of China mainland, and it’s in region of106°E～124°E,30N°N～43°N, which is the political, economic and cultural center ofChina. This region that is among the Pacifica plate，Philippines plate and India plate,in which tectonic deformation feature is activity since the Cenozoic Time, is one ofearthquake-prone regions in China mainland. On historical records, there have been21～Mw7.9earthquakes and five larger than Mw8earthquakes occurred. Thisregion is composed of Yanshan, North China Plain, LudongHuanghai and the Ordosactive blocks. The movement characteristics of the study is helpful in unstanding theregion’s seismic activity on the Mechanism of the regional tectonic stress fieldand the kinetic mechanism of the research,which has important theoretical andpractical significance.Summarize the block studies in China mainland and adjacent region to get theblock projects in North China. GPS velocity field is constructed based on ChinaCrustal Movement Observation Network. Integrate with the block model anddislocation model to inverse the velocity of the main blocks and faults mainly on theDEFNODE program which is modeling elastic lithosphere block rotation and strains,and locking or coseismics slip on block-bounding faults. The conclusions are asfollow:1. The main blocks’ Euler poles relative to Eurasia Plate are respectively:LudongHuanghai （-69.02°，15.31°，0.12°/Ma）; North China Plain （-51.89°，56.22°，0.21°/Ma）; the Ordos （-70.21°,53.07°,0.19°/Ma）; Yanshan（-88.87°，81.06°，0.60°/Ma）. The rotation velocities are small and clockwise.2. Zhangjiakou-Penlai fault is left lateral as a whole with the speed of～1mm/a.It expresses the difference in the different region, the velocity in the boundarybetween the Ordos and Yanshan is larger than the one in the boundary between NorthChina and Yanshan.3. Shanxi fault is right lateral with the average velocity of1mm/a, which expressthe tension character. 4. Tanlu fault has the slip speed of～1mm/a with high locking ratio.5. The mian faults in North China have high locking ratio which is to explain thereasons of earthquake formation.