海南及邻区现今地壳三维运动特征及地球动力学环境分析

利用海南及邻区1999年以来GNSS资料及1970年以来水准数据获取三维运动速度场,分析地壳运动特征,结合东南亚水平运动背景场分析周缘板块对海南地块及华南地块陆缘速度场的影响。结果表明,海南岛三维运动以白沙断裂为界,岛北部以海口-屯昌为界。华南地块各观测点E向运动速率自西向东逐渐减小,至陆缘区域速率最小,各观测站间运动速率差异性小;S向运动速率自西向东逐渐增大;位于23°~26°N区域观测点的速度场与其南北两侧存在差异。华南地块运动受印度板块与欧亚板块碰撞和挤压影响,陆缘地带还受太平洋板块、菲律宾海板块活动及南海扩张运动影响,澳大利亚板块对区域运动影响较小。

Analysis of Present-Day Crustal 3D Movement and Geodynamic Environment in Hainan Island and the Adjacent Area

We analyze characteristics of present-day crustal 3D movement with GNSS data since 1999 and precise leveling data since the 1970s from Hainan island and the adjacent area. Combining these data with the horizontal movement field in the region of southeast Asia, we discuss how horizontal velocity in Hainan and the continental margin of the south China block(SCB) are influencedby surrounding tectonic plates. The results show that 3D movement of Hainan island is bounded with the Baisha fault, and the boundary of that in north island is Haikou-Tunchang line. The values of the east movement of SCB decrease from west to east, the rates of the epicontinental stations are smallest and their differences are smaller. The values of the south movement increase gradually from west to east. The velocities of stations at 23°~26° N(west of Taiwan island) are different from that of those stations on its north and south. The movement of SCB is affected by Indo-European collision and extrusion, the continental margin affected by movement of the Pacific Ocean and the Philippine sea plate, and the expansion of the south China sea(SCS). The Australia plate has less impact on the regional movement.