汶川地震前后川滇及其邻区GPS水平运动演化特征

Evolution Features of Crustal Horizontal Movement from GPS Observation in Sichuan--Yunnan Region and Its Adjacent Area before and after the Wenchuan Earthquake

摘要:

利用川滇及其邻区2004-2007年、2007-2009年GPS水平运动观测资料,对汶川地震前、震时与震后地壳运动及主要活动断裂带构造变形演化特征、汶川地震可能的同震与震后影响进行了分析。结果表明:2007-2009年汶川震区呈现出显著的右旋逆冲同震变形;大震在一定程度上对甘川交界及其北侧的西秦岭构造区、安宁河—则木河断裂的构造运动有所促进;对鲜水河断裂构造运动总体反映调整影响但对其南段可能有促进作用。

Abstract:

Based on the horizontal velocity data observed by GPS during 2004-2007 and 2007-2009, before and after the Wenchuan earthquake, in Sichuan-Yunnan region and adjacent area, the tectonic deformation evolution features of the crust and main active fault belts, and possible influence from the Wenchuan great earthquake, are analyzed. The result shows that the Wenchuan earthquake area showed obvious co-seismic thrust and dextral deformation during the period of 2007-2009. The earthquake, in a certain extent, promoted tectonic movements in Gansu-Sichuan boundary area, as well as West Qinling Mountain area and Anninghe-Zemuhe faults. Meanwhile, impacted tectonic movement on Xianshuihe fault with adjustment overall but may increase the southern section of it.