As large earthquakes in contractional fold-and-thrust belts are usually associated with complex ruptures along multiple faults or fault splays, the evaluation of potential rupture extent and relevant hazards continues to be challenging. We present a case study on the geometry and kinematic evolution of the southern Junggar fold-and-thrust belt, northern Tian Shan, where the 1906 M 8 Manas earthquake occurred. Our interpretations of seismic reflection profiles acquired during oil and gas exploration demonstrate that multiple detachments played significant roles in controlling the structural segmentation. We speculate that seismic potential in active fold-and-thrust belts can be under-estimated by relying on the mapped surface fault traces. Structural analysis of subsurface images in sufficient detail may provide important insights into seismic hazard evaluation and hence complement traditional paleo-seismic studies, particularly in densely populated regions such as the city of Urumqi.

中文翻译：

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北天山南准噶尔褶皱冲断带构造发育多支离体的控制：对地震灾害评估的意义

由于收缩褶皱冲断带中的大地震通常与沿多个断层或断层张开的复杂破裂有关，因此对潜在破裂范围和相关危害的评估仍然具有挑战性。我们提出了一个关于南准噶尔褶皱冲断带、北天山的几何学和运动学演化的案例研究，其中 1906 M8 玛纳斯地震发生。我们对石油和天然气勘探过程中获得的地震反射剖面的解释表明，多个拆离在控制结构分割方面发挥了重要作用。我们推测，依靠绘制的地表断层痕迹可能会低估活动褶皱冲断带的地震潜力。对地下图像进行足够详细的结构分析可以为地震危险性评估提供重要的见解，从而补充传统的古地震研究，特别是在乌鲁木齐市等人口稠密地区。