现今绝对板块运动(英文)  

Current Absolute Plate Motions

作　　者：魏子卿[1] 

机构地区：[1]西安测绘研究所,陕西西安710054

出　　处：《地球科学与环境学报》2009年第4期331-343,共13页Journal of Earth Sciences and Environment

摘　　要：根据热点假设,热点对于中间层是固定的。相对热点的板块运动叫做绝对板块运动。绝对板块运动模型可以通过反演火山链传播的速率和走向数据以确定相对板块运动在角速度空间的原点来得到。利用一组近来(0～7.8Ma)全球分布的热点的迁移速率和走向数据,结合板块运动模型NNR-NUVEL1A,已研制出一个叫做APM2的现今绝对板块运动模型。按照该模型,太平洋板块围绕60.063°S、102.210°E处的极以(0.8330°±0.0133°)/Ma的速率运动,非洲板块围绕46.849°N、44.372°W的极以(0.1015°±0.0134°)/Ma的速率运动,南极板块的运动则以46.871°N、146.942°E为极,速率为(0.0846°±0.0177°)/Ma,欧亚板块的运动更慢,极为27.291°N、171.925°W,速率为(0.0655°±0.0206°)/Ma。这一模型表明,岩石圈相对深部地幔有一个以49.423°S、90.625°E为极,速率为(0.1983°±0.0135°)/Ma的净旋转。表明太平洋热点同印度—大西洋热点不一致,显示太平洋热点的运动也不一致。为了分析和比较,还给出了仅用全球分布的热点的走向数据和仅用印度-大西洋热点的走向数据得到的板块绝对运动的角速度。The plate motions with respect to the hotspots, which are fixed relative to the mesosphere according to the hotspot hypothesis, are called absolute. The absolute plate motion model can be achieved by inverting the data set of the propagation rates and/or trends of volcanic chains to determine the origin in the angular space for the relative plate motion. A current absolute plate motion model designated as APM2 has been developed using a data set of migration rates and trends of recent （0-7.8 Ma） globally distributed hotspots tracks in conjunction with the plate motion model NNR-NUVEL1A. According to this model, the Pacific plate is moving at a rate of （0. 833 0°±0. 013 3°）/Ma about a pole at 60. 063°S, 102. 210°E;Africa has a motion of （0. 101 5°±0. 013 4°）/ Ma about 46. 849°N, 44. 372°W;Antarctic has a motion of （0. 084 6°±0. 017 7°）/Ma about 46. 871°N, 146. 942°E; Eurasia has an even slower motion of （0. 0655°±0. 0206°）/Ma about 27. 291°N, 171. 925°W. The model shows that the lithosphere has a net rotation of （0. 198 3°±0. 013 5°）/Ma about 49. 423°S,90. 625°E with respect to the deep mantle. It is demonstrated that the Pacific hotspots are inconsistent with the Indo-Atlantie hotspots. Also, it is shown that the Pacific hotspots involved appear do not have a coherent motion. For analysis and comparison, this paper also gives the angular velocities of absolute plate motions obtained from only trend data for global distributed hotspots and from only trend data for only Indo Atlantic hotspots.

关 键 词：绝对板块运动 热点 热点参考架 无净旋转参考架 岩石圈的净旋转 

分 类 号：P227[天文地球—大地测量学与测量工程]