Global Plate Tectonic Motion From GPS Measurements

The tectonic plate motions, especially at the convergent edge of the lithospheric plate, such as Building Mountain, earthquake eruption, island-arc and trough development, and so on, which are close related on the human inhabiting environment. In the past, the traditional method is with geophysical method to research motion and interrelation of tectonic plate, explore the evolution process and dynamics mechanism, and speculate the motion characteristics of tectonic plate with geological data spanning millions of years. However, most of these conclusions stay at the level of hypothesis and guess. With the rapid development of space geodetic techniques at recent 20 years, the new space geodetic data and new analytical techniques inaugurate the new route to monitor and study crustal motion and dynamicvariety of global tectonic plate In this paper we present the current characteristics of global tectonic plate in short time scale and crustal deformations of regions mainly based on GPS data(incorporating few data of VLBI and SLR). Main conclusion and content of this paper is as follows: (1) The research methods of modern crustal motion from rigid body to elastic and fluid body are generalized systemically, and its progresses are reviewed; Furthermore, the insufficiencies and unsolved questions of geological method researching modern crustal motion are presented, and GPS techniques play an important role in the research of modern crustal motion. (2) The high accurate plate motion model of ITRF2000VEL is obtained with appropriate observation sites whose deformations close in upon the rigid motion of plate through circulations of many times, and then several absolute plate motion models are established and evaluated. (3) We lucubrated and analyzed in detail the deformation of sites relative to the Asia plate and the motion of tectonic blocks in Asia. In addition, the crustal motion and deformation of the Pacific, North America, Australia, South America and Philippine plate, are also analyzed. (4) The collision zones of Eurasia are very complicated due to the extrusion of continent lithospheres and the subduction between the oceanand continent lithospheres, and we analyze the mutual effects of different lithospheres and the crustal deformation features of collision zones (5) Firstly we give the present-day spreading velocity of the mid-Atlantic ridge. Comparing them predicted fromgeological data in millions of yearsdisplays the present-day motion characteristics of the mid-Atlantic ridge that the mid-ridge of the South Atlantic, whose spreading is slowing down, spreads faster than the North Atlantic, whose spreading is speeding up. (6) The relative motions of global plate tectonics are analyzed in detail with space geodetic and geological data. In addition, we find that the Southern Hemisphere is expanding and decelerating systematically, the Northern Hemisphere is compressing without a systematical change, and the whole Earth is periodically fluctuating, which show global plate tectonic motion is asymmetrical. (7) The non-linear motion of global plate is studied in detail using continuous GPS time series, and the temporalvariablefeature of plate Euler rotation motion is firstly presented internationally.