At present, the criteria for selecting space geodetic sites are random and uncertain internationally. In this paper, we present a new method for selecting rigid geodetic sites of each plate and establishing a present-...At present, the criteria for selecting space geodetic sites are random and uncertain internationally. In this paper, we present a new method for selecting rigid geodetic sites of each plate and establishing a present-day relative motion model of global plates: RM2000. Incorporating geomagnetic anomaly data 80 MaBP, the relative Euler vectors of global plates in different ages can be determined, based on, which the spreading, sliding and converging rates of adjacent plates can be obtained. Comparing them shows: (1) in the recent 10 Ma, the relative motions of adjacent plates have been systematically slowing down in the South Hemisphere, and have no, systematical variations in the North Hemisphere; (2) in the entrie 80 Ma, the relative motion trends of Australia-Antarctica, Pacific-Antarctica, Africa-Australia and Australia-Eurasia have been accelerative, the relative motion trends of mid-Atlantic ridge, Africa-Antarctica, Cocos-Pacific, Africa-Eurasia and India-Eurasia have been slowing down, and the relative motion trends of Pacific-Nazca, Nazca-South America, Pacific-Australia and Pacific-North America, have been almost constant.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.40174009)the National Important Basic Research Project(Grant No.G1998040703)Open Research Fund Program of the Key Laboratory of Geospace Environment and Geodesy,Ministry of Education,China(Grant No.030405).
文摘At present, the criteria for selecting space geodetic sites are random and uncertain internationally. In this paper, we present a new method for selecting rigid geodetic sites of each plate and establishing a present-day relative motion model of global plates: RM2000. Incorporating geomagnetic anomaly data 80 MaBP, the relative Euler vectors of global plates in different ages can be determined, based on, which the spreading, sliding and converging rates of adjacent plates can be obtained. Comparing them shows: (1) in the recent 10 Ma, the relative motions of adjacent plates have been systematically slowing down in the South Hemisphere, and have no, systematical variations in the North Hemisphere; (2) in the entrie 80 Ma, the relative motion trends of Australia-Antarctica, Pacific-Antarctica, Africa-Australia and Australia-Eurasia have been accelerative, the relative motion trends of mid-Atlantic ridge, Africa-Antarctica, Cocos-Pacific, Africa-Eurasia and India-Eurasia have been slowing down, and the relative motion trends of Pacific-Nazca, Nazca-South America, Pacific-Australia and Pacific-North America, have been almost constant.
