川滇菱形块体东边界断裂带内库仑应力演化及危险性

发布时间：2018-04-18 21:46

本文选题：川滇菱形块体东边界 + 震后黏滞松弛　；参考：《地震地质》2017年03期

【摘要】：采用分层黏弹模型,考虑了川滇菱形块体东边界1480年以来34个强震和大地震的同震位错和震后黏滞松弛效应,以及各断层段的震间长期构造加载作用,计算了川滇菱形块体东边界18个断层段的断层面上的库仑应力变化随时间的演化。系统地研究了川滇菱形块体东边界鲜水河、安宁河、则木河、小江断裂带间的相互作用,分析断裂带各断层段之间、各断裂带之间先发生的地震对后发生地震的促进或延迟作用,进一步基于断层面上的库仑应力变化计算结果分析各断层段的强震危险性。应力触发的计算结果显示,各断裂带各断层段上先发生的强震可能触发后发生的强震,相邻断裂带上发生的强震之间也可能存在触发作用。各断层段上累积库仑应力变化随时间演化的计算结果显示,鲜水河断裂带的中段及南部磨西段、安宁河断裂带冕宁—西昌段、小江断裂带北部巧家—东川段和南部建水段的库仑应力增加显著,强震危险性值得关注。
[Abstract]:Using stratified viscoelastic model, the co-seismic dislocation and post-seismic viscosity relaxation effects of 34 strong earthquakes and large earthquakes since 1480 years in the east boundary of Sichuan-Yunnan rhombic block are considered, as well as the long-term tectonic loading of each fault segment.The evolution of Coulomb stress over time on the fault plane of 18 fault sections at the east boundary of the Sichuan-Yunnan rhombic block is calculated.The interaction between Xianshuihe, Anning River, Zemu River and Xiaojiang fault zone in the east boundary of Sichuan-Yunnan rhombic block is studied systematically.The first occurrence of earthquakes among the fault zones promotes or delays the occurrence of earthquakes, and the strong earthquake risk of each fault segment is further analyzed based on the Coulomb stress variation calculation results on the fault plane.The calculation results of stress triggering show that the strong earthquakes that occur first in each fault zone may trigger the strong earthquakes after triggering, and there may also be triggering effects among the strong earthquakes occurring in the adjacent fault zones.The calculated results of cumulative Coulomb stress evolution over time in each fault section show that the middle and southern Moxi sections of the Xianshuihe fault zone, the Mianning Xichang section of the Anning River fault zone,The Coulomb stress of Qiaojia-Dongchuan section and southern Jianshui section in the north of Xiaojiang fault zone increases significantly, and the risk of strong earthquake should be paid attention to.
【作者单位】：中国地震局第二监测中心;西安测绘总站;
【基金】：国家自然科学基金(41604015) 中国地震局实验场项目(20150115)共同资助
【分类号】：P315.2

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