上海VLBI站相对于欧亚板块运动的测定与讨论

利用 1 988～ 1 996年共 8年的上海天文台 VLBI站与国际 VLBI站基线长度变化的精确测定结果 ,重新估计了上海 VL BI站的形变速率 ,证实了基于不同地球参考架系统对估计的上海站的运动有明显差异 ;基于最新的 ITRF96地球参考架和 Sillard等 (1 998)欧亚板块的欧拉矢量 ,估计得到上海站的地壳垂直形变速率为 -1 .95± 1 .0 2 mm/a呈下降趋势 ,水平形变速率为 1 3.5 5± 1 .2 0 mm/a,方位 77.5°± 4.5°;估计得到乌鲁木齐 VL BI站的地壳垂直形变速率为 -6 .0 8± 2 .77mm/a呈下降趋势 ,水平形变速率为 2 1 .87± 2 .5 2 mm/a,方位 45 .5°±6 .6°;进一步分别基于 NNR-NUVEL -1 A地球板块运动模型和 Zhang等 (1 999)的欧亚板块的欧拉矢量 ,得到与上述较一致的结果

Determination and Discussion of Motion of Shanghai VLBI Station Relative to Eurasian Plate

Using the changing rates of baseline lengths between Shanghai andeight international VLBI stations determined from 1988 to 1996, the deformation rates of Shanghai VLBI station are re-estimated. It is verified that the difference between the results of deformation rates, estimated basing on the different terrestrial reference frame system, is relatively large. Based on the international terrestrial reference frame, the ITRF96 and the Euler vectors of Eurasian plate by Sillard et al.(1998), the vertical deformation rate of Shanghai VLBI station is obtained as -1.95±1.02 mm/a(sink), the horizontal component is 13.55±1.20 mm/a with its local AZ 77.5°±4.5°; the corresponding results for Urumqi VLBI station are -6.08±2.77 mm/a, 21.87±2.52 mm/a with its local AZ 45.5°±6.6°. Based on the Euler vectors of Eurasian plate of the NNR-NUVEL-1A and Zhang et al.(1999), respectively, the similar results as mentioned above are estimated, which show no notable difference.