利用GNSS资料研究新源-和静MS6.6地震前后地壳形变与地震关系

Relationship between Crustal Deformation and Earthquake Activitiesbefore and after the Xinyuan-Hejing MS6.6 Earthquake Using GNSS Data

摘要:

利用2009-2011年三期GNSS观测资料,获得新源-和静6.6级地震前后震中附近区域水平运动速率、主应变率、面膨胀率及最大剪应变率,分析得出:(1)研究区整体呈挤压缩短趋势,南部区域运动速率总体高于北部,而中部区域运动速率高于东西两侧,这与区域构造特点有关。新源-和静M_S6.6地震之后,研究区西北部区域的应力场能量得到较大的吸收和释放。(2)从研究区应变分析中可以看出,沿断层出现的主应变率正负交替区域与地震的发生有一定关系。从面膨胀等值线图可以看出,两个面收缩区之间区域是地震发生的重要区域。剪应变区域变化可以反映出地震的破裂方向。

Abstract:

Based on an examination of three stages of global navigation satellite systems (GNSS) observation data from 2009 to 2011, we obtained the horizontal movement velocity, principal strain rate, surface expansion rate, and maximum shear strain rate around the epicenter area before and after the Xinyuan-Hejing M_S6.6 earthquake of 2012. The results show that (1) the main movement trend in the research area is a reduction in the horizontal movement rate from south to north. The movement rate in the southern region is higher than that in the northern region, and the movement rate in the central area is higher than those in the east and west regions. (2) The positive negative alternate zone of the principal strain rate along the fault has some relationship with the earthquake. Between the two surface shrinkage areas is an important earthquake area. The regional change of the shear strain rate can reflect the direction of earthquake rupture.