汶川地震对芦山地震孕震环境影响的数值模拟

发布时间：2018-05-25 05:41

本文选题：汶川地震 + 芦山地震　；参考：《科学通报》2017年17期

【摘要】：利用有限元数值模拟方法,以汶川地震和芦山地震的野外地质调查、同震位移和汶川地震前形变观测结果为约束,分析研究了高海拔地形蓄积的重力位能作用下,中地壳低速层的存在以及中央断裂和前山断裂同时破裂的条件下汶川地震的发生对龙门山南段孕震环境的影响.模拟计算结果显示,在一定的模型壳幔介质属性及空间结构下,龙门山断裂带西侧低速层的存在、青藏高原向四川盆地过渡带的地形特征以及汶川地震时中央断裂和前山断裂同时破裂的条件,是控制汶川地震对芦山地震孕震环境影响程度的重要因素.其中,地形和低速层对汶川地震引发的芦山地震孕震环境库仑破裂应力变化的影响最为显著,在所选剖面的北东段,地形特征的影响更为明显,而汶川地震双破裂面的影响则较小.
[Abstract]:Based on the field geological survey of Wenchuan earthquake and Lushan earthquake, the results of deformation observation before the Wenchuan earthquake and the Wenchuan earthquake, the finite element numerical simulation method is used to analyze and study the gravity potential energy of the high elevation topographic accumulation. The impact of Wenchuan earthquake on the seismogenic environment of the south Longmen Mountain under the condition of the existence of low velocity layers in the middle crust and the simultaneous rupture of the central fault and the Qianshan fault. The simulation results show that the low-velocity layer on the west side of the Longmenshan fault zone exists under certain model crust-mantle medium properties and spatial structure. The topographic characteristics of the transitional zone from the Qinghai-Tibet Plateau to the Sichuan Basin and the conditions for the simultaneous rupture of the central fault and the Qianshan fault during the Wenchuan earthquake are the important factors controlling the impact of the Wenchuan earthquake on the earthquake preparation environment of the Lushan earthquake. Among them, the influence of topography and low velocity layer on the Coulomb rupture stress change of Lushan earthquake induced by Wenchuan earthquake is the most significant, and the influence of topographic characteristics is more obvious in the northern and eastern section of the selected section. The effect of double fracture surface of Wenchuan earthquake is relatively small.
【作者单位】：中国地震局地球物理研究所;中国地震局地震观测与地球物理成像重点实验室;
【基金】：中国地震局地震行业科研专项(201408014);中国地震局基本业务专项(DQJB16B06) 国家自然科学基金(41504079)资助
【分类号】：P315.2

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