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以往的研究显示了2013年芦山MS7.0级地震发震断层的隐伏逆冲断层基本特征,但是破裂深部细节差异较大.本文以近场密集的同震形变数据约束芦山地震破裂面几何形状及滑动分布,结果显示芦山地震破裂面具有铲状结构,上部16km为43°~50°高角度断层,深部16~25km为小于27°的低角度断层,破裂深度与重定位的余震分布深度一致.破裂分布模型清楚显示上下两个断层上各有一个滑动幅度大于0.5m的峰值破裂区,最大滑动量1.5m位于13km深处.重定位的余震分布基本都落在最大滑动量等值线外部库仑应力增加的区域.芦山地震破裂面几何形状和滑动分布特征与2008年汶川MS8.0级地震映秀—北川破裂相似,支持龙门山冲断带发育大规模的近水平滑脱层,是青藏高原东缘地壳缩短增厚、龙门山挤压隆升的重要证据.
Previous studies have shown the basic features of the buried fault of the Lushan MS7.0 earthquake in 2013, but the details of the deep rupture are quite different.In this paper, the near-field coseismic deformation data constrain the geometry and sliding The results show that the rupture surface of Lushan earthquake has a shovel-like structure. The upper 16km is a 43 ° ~ 50 ° high-angle fault and the deep 16 ~ 25km is a low-angle fault that is less than 27 °. The rupture depth is consistent with the aftershock aftershock distribution. The distribution model clearly shows that each of the upper and lower faults has a peak rupture zone with a sliding amplitude of more than 0.5 m, with the maximum slip 1.5 m located at a depth of 13 km. The aftershock distribution of the relocations mostly falls outside the maximum slip contour contour Coulomb stress The Lushan earthquake rupture surface geometry and slip distribution characteristics are similar to the Yingxiu-Beichuan fault in the 2008 Wenchuan Ms8.0 earthquake, supporting the development of large-scale near-horizontal slip detachment in the Longmen Shan thrust belt, Shortening thickening, Longmen Hill extrusion uplift important evidence.