环渤海及营口-潍坊断裂带位移场演化特征

针对渤海周边地区及营口-潍坊断裂带,收集并统一处理该地区1999年以来的GPS数据,依据最新的观测成果跟踪该区域地壳运动的动态变化;采用块体运动方程计算营口-潍坊断裂带的活动速率,并分析该断裂带的活动性质。结果表明,1999-2010年营口-潍坊断裂带为右旋,2011-2013年为左旋,日本3·11地震使北北东向营口-潍坊断裂带改变了走滑活动性质,反映了3·11地震使华北东部区域应力场有明显地变化,也表明华北地区的构造活动受印度-欧亚碰撞带和太平洋-欧亚板块俯冲带的活动程度制约。日本3·11大地震使本区拉张显著,应变能有一定卸载性变化。本文的研究结果对于理解营潍断裂带地震活动性与规律及区域动力学状况具有一定的参考价值。

Movement field of Bohai Sea and its surrounding region and evolution characteristics of Yingkou-Weifang fault

In view of Bohai Sea and its adjacent area,by collecting and united computing GPS data from 1999 in this region,the article tracks dynamic variations of the crustal movement in this area based on the latest observation achievements.Using block motion equations,the paper calculates the activity rate of Yingkou-Weifang fault,and analyzes activity characteristics of the fault.The results suggest:Yingkou-Weifang fault was right lateral in 1999-2010,and left lateral in 2011-2013,the nature of slip activity of NNE-trending Yingkou-Weifang fault changed because of the influence of 3 · 11 Japan Earthquake,which reflects that significant variations of the regional stress field of the east area of North China due to 3 · 11 Japan Earthquake,also shows that the tectonic activities in North China are limited to the activity degree of India-Eurasia collision zone and Pacific-Eurasia subduction zone.The activity is significantly pull apart in the research area because of 3 · 11 Japan Earthquake,and the strain energy has unloading variations to certain extent in this area.The research result of this paper has a certain reference value for understanding seismic activity of Yingkou-Weifang fault and regional dynamics status.