Study On The Velocity Field Of Crustal Horizontal Movement In Bohai Sea Area

The traditional method of geological and geophysical studies on the crustal movement is used to describe the crustal movement, geological geophysical data accumulated with some mathematical methods.However because of the time span, material shortage and other shortcomings, the method is facing a huge challenge. Since the development of modern geodetic instruments, especially the development of GPS technology makes real-time monitoring of crustal movement is possible, and it has important significance for study of regional tectonics, crustal movement and deformation prediction of earthquakes and other natural disasters.In this paper, the theory and method of establishing the regional crustal velocity field of GPS data obtained by modern geodetic survey are systematically studied. Based on the data of the GPS monitoring station in the Bohai area (30 N?45 CMONOC, N, E-129, E), using the China tectonic environment monitoring network. The Euler vector method are used to establish the model of the whole and the block velocity field in the Bohai Rim region, and the accuracy of the methods is compared. Finally, the optimal velocity field in the Bohai sea area is obtained, which provides some help for the study of crustal deformation in the Bohai area.The main research contents include:(1)Analyze the principles and characteristics of the Euler vector method and the fitting methods of the traditional rigid motion model.Based on the recent GPS observation data of CMONOC,using Euler vectormethod and inverse distance weighted method, Kriging method,minimum curvature method and nearest neighbor method, natural neighbor method, linear triangulation method 6 fitting method totally to establish field model the overall velocity of Bohai rim region.We calculate and summarize the modeling results of all the methods above,and then compare the accuracy and characteristics of each method with the method of checking the inner core of all the models.(2) To study the division of plate in mainland China, according to the distribution of the geological structure, seismic belt and fault zone in the Bohai Rim region, the sub-block of the Bohai Sea area is divided on the basis of the second-level plate division in mainland China, and To test the rationality and correctness of its division.(3) The sub-block modeling is carried out by using the Euler vector method and the inverse distance weighting method, the kriging method and the minimum curvature method in the Bohai Rim region, and the sub-block selection is the highest The velocity field of the whole velocity field and the secondary block boundary of the Bohai Sea region is plotted by GMT, and the motion state of each sub - block and block boundary is analyzed.