近10年来中国大陆GPS水平运动与构造变形特征

CHARACTERISTICS OF GPS HORIZONTAL MOVEMENT AND TECTONIC DEFORMATION DURING CURRENT TEN YEARS IN CHINA MAINLAND

利用1999-2009年中国大陆GPS水平运动速度场资料,对近10年来地壳水平运动及主要活动断裂带构造变形特征、昆仑山口西8.1级与汶川8.0级地震变形及其可能影响进行了分析。结果表明:①昆仑山口西与汶川地震同震变形显著,可能在一定程度上促进东昆仑构造带东段及甘川—甘川陕交界,鲜水河断裂带南段、安宁河断裂带中北段及与龙门山断裂带交汇区附近与其构造背景一致的断裂活动及应变积累。②中国大陆主要活动断裂带构造变形特征总体上与其地质背景一致;近10余年来未发生7级以上大震,可能存在长期孕震背景的区域主要位于新疆西部、藏东至滇西—滇西南、东昆仑断裂带东段至甘川—甘川陕交界、安宁河断裂带及其附近区域。

Using horizontal velocity field result observed by GPS during 1999—2009 of China Mainland,the characteristics of horizontal crustal movement and tectonic deformation at main fractures during current 10 years were analyzed,together with co-seismic deformation of the Kunlunshan and Wenchuan earthquakes and their possible influence.The results show that： ①Co-seismic deformation of the Kunlunshan and Wenchuan earthquakes was obvious,possibly had promoted fracture activity and strain accumulation,at eastern segment of eastern Kunlunshan fracture,at boundary between Gansu and Sichuan,at boundary between Gansu and Sichuan and Shaanxi,at southern segment of Xianshuihe fracture,at middle-northern segment of Anninghe fracture and its meeting region with Longmenshan fracture,according with their tectonic background to some degree.②The main features of tectonic deformation at main active fractures in China Mainland were consistent with their geological background;for current 10 years,the regions where no earthquakes with Ms≥ 7 occurred and existed long-time background of earthquake development,mainly were located in the western Xinjiang,the eastern Xizang to the western-southwestern Yunnan,and eastern segment of eastern Kunlunshan fracture,boundary between Gansu and Sichuan,boundary between Gansu and Sichuan and Shaanxi,Anninghe fracture and its nearby.