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2010年4月我国青海省玉树藏族自治州的玉树县发生了Ms7.1级地震,这次地震(震中33.2°N 96.6°E,Ms=7.1)是由甘孜-玉树断层的强烈活动引起。甘孜-玉树断裂带大部分分布于青海-西藏高原,北西走向。该断裂带和鲜水河断裂带共同组成了巴颜喀拉地块的南边界,二者在甘孜附近成左阶错列分布。在区域构造背景分析和卫星图像、航片解译的基础上,本文给出了玉树地震地表破裂带的空间展布特征。利用D-InSAR(合成孔径雷达差分干涉测量)技术获得了玉树地震的同震形变场,继而得到了地震引起的LOS向的地表位移和发震断层的大致位置。通过对玉树地震同震形变场的分析得到本次地震的动力学特征为明显的左旋走滑。另以同震形变场和发震断层的初始模型,模拟了本次地震的同震形变场,同时通过边界元反演方法得到了断层的特征参数。反演得出的结论和野外调查的结果基本一致。
In April 2010, an Ms7.1 earthquake occurred in Yushu County, Yushu Tibetan Autonomous Prefecture of Qinghai Province. The epicenter (33.2 ° N 96.6 ° E epicenter, Ms = 7.1) was caused by the intense activity of the Ganzi-Yushu fault. Most of the Ganzi-Yushu fault zones are located in Qinghai-Tibet Plateau and move northwestwards. Together with the Xianshuihe Fault, the fault zone and the Xianshuihe fault zone form the southern boundary of the Bayan Harness, with a left-staggered distribution near the Garze area. Based on the analysis of regional tectonic setting and interpretation of satellite images and aerial photos, this paper presents the spatial distribution characteristics of the surface rupture zone of the Yushu earthquake. The coseismic deformation field of Yushu earthquake was obtained by using D-InSAR (Differential Interferometry), and the LOS-induced surface displacements caused by the earthquake and the general location of the seismogenic fault were obtained. Through the analysis of the coseismic deformation field of Yushu earthquake, it is found that the dynamic characteristics of this earthquake are obvious left-lateral strike-slip. In addition, the coseismic deformation field and the initial model of seismogenic fault are simulated to simulate the coseismic deformation field of this earthquake, and the characteristic parameters of the fault are obtained by the boundary element inversion method. The results obtained from the inversion are basically the same as those from the field survey.