Gravity Changes Caused By The Coupling Movement Between Crustal Deformation And Its Density Change

Migration and crust deformation is an important basis for research topics of continental dynamics and lithosphere plate movement.New research shows that the movement of crustal deformation and material density(flow or migration,etc.)are the two basic forms of crustal movement.Both of them always coupled /get together moving.Surface or space time gravity field is one of the best reflection of the coupling movement.With space geodesy geometry(especially GNSS)and Geodetic observation techniques evolving,We have accumulated a lot of high-precision,high-resolution surface deformation and space-time gravity change data.There is a definite link between this crustal deformation and changes in Earth's gravity field.How to use the results of GNSS and other deformation data to study the contribution of crustal deformation movement of the Earth's gravitational field changes,it is still an important unresolved issue.GNSS,standards and other surface deformation observations show that horizontal and vertical crustal movement rate show significant movement of non-uniform deformation characteristics in mainland of China.what contribution it make to gravity change? How much contribute? Still unclear understanding.The traditional view that the crustal vertical movement can cause gravity changes,But do not think that gravity changes caused by crustal horizontal movement.This may have some theoretical and actual "myths".Through intensive study of crustal deformation displacement(horizontal + vertical)and the relationship of gravity changes,it can make for continental deformation mechanisms and continental dynamics,as well as the mechanism of strong earthquakes important theoretical and practical reference value.In this paper,based on coupling theory of crustal deformation and density changes,gravitational potential field is derived relationship between space and time variation of surface deformation caused by the movement of a fixed point.Followed by numerical integration method for integrating discrete formula,three-dimensional model forward modeling,and in the Southeast of Tibetan Plateau,with actual rate obtained by GPS,Crustal structure model and deformation of deep research,We simulated and research variation of gravity caused by crustal deformation,.The main content of the work and results are as follows:1)This paper summarizes the research and development of crustal deformation and density variations of the basic theory of coupled motion,including theory and methods of Walsh,Reilly & Hunt,Chen Yun Tai and Shen Chong Yang et al,and mutual connection and their characteristics.2)According to the coupled motion theory of crustal deformation and density changes,with two methods we derived the gravitational potential field of analytical formulas strict exercise-induced deformation space by a fixed-point and fixed-point surface.3)To achieve the time-varying gravitational potential field caused by the movement of the deformation space a fixed point solution method: Basic theory and numerical integration of mathematical knowledge in the calculation of the deformation caused by the movement of gravity changes,Several major numerical integration methods,including Newton-Coster formula,Compound quadrature formula and Multiple quadrature formula,etc.On this basis,Preparation of crustal deformation and density changes coupled motion numerical model program(Composite trapezoidal multiple integral),and we used reasonable translational motion of vertical rectangular translational motion analytical model to calculate the test program.The results show that two algorithms consistent value changes in the milligal precision,and graphics changes similarly.It explains that calculation is correct.4)In the Southeast of Tibetan Plateau,It describes the tectonic context of the region.Based on coupling theory of crustal deformation and density changes,Using GPS velocity information of the area and CRUST1.0 regional data(Their applicability has discussed),with crust-mantle double layers models,it calculated the gravity changs caused by the movement of the crustal deformation,and analyzed the main features of the region's gravity changes.The models combine geodynamic mechanism in the region for a certain of interpretation.Simulation results showed that gravity changes caused by crustal horizontal movement can reach the milligal dimension.