利用最小二乘配置方法研究张家口-渤海地震带周边地区应变场

摘要

利用张家口-渤海地震带周边地区1999、2001、2004、2007、2008、2009年6期143个GPS站的流动观测数据,给出了1999-2009年张家口-渤海地区水平形变运动速度场,并应用最小二乘配置方法获得了区域应变场分布图像和形变图像.区域形变分布初步显示:1)相对于欧亚板块,其年平均最大变化为5 ～6 mm/a;2)张家口-渤海地震带具有2.0 mm/a左右的左旋走滑运动,其耦合深度为25 ～45 km;3)研究区内最大剪切应变为3×10-8/a,高值区集中在北京-天津及唐山地区.%We collected and combined all mobile GPS data between 1999 and 2009 around Zhangjiakou-Bohai seismic belt, and obtained the velocities at 143 stations. At the same time,we constructed a regional strain field of the Zhangjiakou-Bohai seismic belt region with least-square collocation, and investigated the slip rate of Zhangjiakou-Bohai belt. The study results show that; 1 ) the regional maximum displacement is about 5 mm/a,2) Zhangjiakou-Bohai seismic belt is creeping in with left-lateral slip rate of 2. 0 mm/a and the creeping depth is in a range of 25 -45 km,3) The maximum shear strain is 3 X 10 /a in Beijing-Tianjin and Tangshan area.