Space Geodynamics Research

As a crossing and deriving subject, the fields and contents of geodynamics are amplitude and abundant. Due to the development of GPS, which is representative of spatial geodetic measure technology, it is possible to detect and study the movement of our Earth. And part fields have been realized in geodynamics. Therefore, applying the spatial geodetic methods into various fields of geodynamics is of scientific and practical importance.This dissertation presents the detection of global tectonic change by space geodetic data. And the establishment of plate motion model is also studied. First, the development and status of plate motion and terrestrial reference system are introduced; then the fundamental and geodetic measurement of plate motion is discussed; at last, the realization and transformation of terrestrial reference system is deduced; which provide theoretical basis to interrelated study of this article.Before the plate motion model is established by geodetic data, it is necessary to present the derivation and disposing process of data used in this text. Then the plate motion model GVM1 with respect to the unifying data of GPS and VLBI is established, and also present the absolute and relative euler vector of 12 plates and more than 20 conjugated plates with their error ellipse, comparison with the geological plate motion model NUVEL-1A indicates that the plate motions from space geodetic observations are generally consistent with those from geological observations in recent 3 million years.GPS and VLBI is complete different observed technology, so the crustal motion deduced from them may be absolute unlikeness. The baseline length rates of co-located sites are calculated by GPS and VLBI data respectively, whose comparison by mathematic statistic is also made, and their system error and constant value are offered too.The unsymmetrical global tectonic change deduced from geophysical research is identified by space geodetic data from GPS and VLBI measurement. Whatever using geodetic rates, or using vertical velocities of stations, two kinds of data and their integration give the consistent results, which testified that the Northern hemisphere may be in contracting change, while the South may be in expanding change. And the changing level and range is also presented.The Earth volume and geometry change are detected. Based on geodetic data from GPS and VLBI stations, using Delaunay arithmetic in digital terrain model to form series of triangles to approach the Earth terrain, the Earth's volume and geometry change are studied, and also using plate motion model interpolation to improve stations distribution. The results show that geodetic and interpolated data given the consistent conclusion. The deformation patterns indicate that the Earth is still undergoing asymmetrical deformation, and thus changing direction and level is introduced.Finally, the influence of ground spots derived from postglacial rebound is studied. The vertical and horizontal postglacial rebound is detected by measuring site velocities and length rates of baselines respectively using data from space geodetic measurement of VLBI. The comparison and correlation analysis between space geodetic results and predictions of postglacial rebound from the geophysical model ICE-4G is shown. And the system error between space geodetic results and ICE-4G predictions is also discussed.