Sentinel-1 observations of the 2016 Menyuan earthquake: A buried reverse. event linked to the left-lateral Haiyuan fault
Sentinel-1 observations of the 2016 Menyuan earthquake: A buried reverse. event linked to the left-lateral Haiyuan fault
复制标题
Sentinel-1 对 2016 年门源地震的观测：埋藏反转。
DOI：
10.1016/j.jag.2017.04.011
复制
发表时间：
2017
影响因子：
7.5
通讯作者：
Shao Z.
中科院分区：
文献类型：
--
作者：
Wang H.;Liu-Zeng J.;Ng A. H. -M.;Ge L.;Javed F.;Long F.;Aoudia A.;Feng J.;Shao Z.
活动构造相互作用的认识是理解大陆变形机制和估计复杂构造背景下地震潜在性的必要条件。在这里，我们使用Sentinel-1A雷达图像来调查与2016年门源（青海）地震相关的同震形变，该地震发生在海原左行断层附近。上升和下降的干涉图表明逆冲为主的滑动，与最大的视线位移为58和68毫米，分别。干涉合成孔径雷达观测结果与均匀滑移位错模型拟合良好，但滑移宽度比大于经验标度律预测值。我们认为，几何复杂性附近的冷龙岭抑制弯曲破裂传播，导致高滑移发生在一个小的区域和更高的应力降比全球估计。虽然干涉合成孔径雷达观测不能区分主平面，我们更倾向于西倾的解决方案，考虑到余震分布和一般的构造背景。干涉合成孔径雷达模拟和余震定位都表明，破裂面与海原断裂在10 km深处相连，这是西藏典型的孕震深度。我们认为，地震更可能发生在一个次级分支在海原断裂的约束弯曲，即使我们不能完全排除它是在北祁连山逆冲断层的一个扇的可能性。
Knowledge on the interaction of active structures is essential to understand mechanics of continental deformation and estimate the earthquake potential in complex tectonic settings. Here we use Sentinel-1A radar imagery to investigate coseismic deformation associated with the 2016 Menyuan (Qinghai) earthquake, which occurred in the vicinity of the left-lateral Haiyuan fault. The ascending and descending interferograms indicate thrust-dominated slip, with the maximum line-of-sight displacements of 58 and 68 mm, respectively. The InSAR observations fit well with the uniform-slip dislocation models except for a larger slip-to-width ratio than that predicted by the empirical scaling law. We suggest that geometric complexities near the Leng Long Ling restraining bend confine rupture propagation, resulting in high slip occurred within a small area and much higher stress drop than global estimates. Although InSAR observations cannot distinguish the primary plane, we prefer the west-dipping solution considering aftershocks distribution and the general tectonic context. Both InSAR modelling and aftershock locations indicate that the rupture plane linked to the Haiyuan fault at 10 km depth, a typical seismogenic depth in Tibet. We suggest that the earthquake more likely occurred on a secondary branch at a restraining bend of the Haiyuan fault, even though we cannot completely rule out the possibility of it being on a splay of the North Qilian Shan thrusts.