2015年新疆皮山M_W6.4地震对周围地区的静态应力影响

发布时间：2018-02-02 10:41

本文关键词： 年皮山地震震源破裂模型库仑应力水平应力　出处：《地震地质》2017年05期 　论文类型：期刊论文

【摘要】：基于2015年皮山M_W6.4地震的破裂模型及均匀弹性半空间模型,计算了该地震在周围主要活动断层上产生的库仑应力变化和周围地区的水平应力变化。结果表明:1)皮山地震造成西昆仑山前逆冲断裂西段库仑应力降低(达9.5×10~3Pa);西昆仑山前逆冲断裂东段和康西瓦断裂中段的库仑破裂应力增加,因此要注意西昆仑山前逆冲断裂东段的危险性。2)对余震位置的统计分析认为,大多数余震受到主震的触发作用;主震造成周围地区库仑引力增加的部分,余震的分布比较密集;而主震造成的库仑应力减少的部分,余震的分布就比较稀疏。3)水平面应力在该地震震中北侧的柴达木盆地和南侧的青藏高原西北部增加(拉张),在震中东侧的青藏高原北部和西侧的帕米尔高原东部降低(压缩)。从水平主压和主张应力方向来看,震中区域的主压应力为近SN向,主张应力方向为EW向。主压应力以震中为中心呈向外辐射状,而主张应力近乎于以震中为圆心的同心圆。震中西侧的主压应力为NW向,震中东侧为NE向,应力的大小随着半径增加而逐渐衰减,中心达107Pa,到达柴达布盆地北部的迈丹断裂仅有百Pa的水平。
[Abstract]:Based on the rupture model and the uniform elastic half-space model of the Mushan W6.4 earthquake on 2015. The Coulomb stress variation on the main active faults around the earthquake and the horizontal stress variation in the surrounding area are calculated. The results show that the Pishan earthquake reduced the Coulomb stress in the western segment of the West Kunlun Mountains thrust fault. Up to 9.5 脳 10 ~ (-3) Paa; The Coulomb fracture stress increases in the eastern segment of the Foreland thrust fault and the middle section of the Kangxiwa fault in the West Kunlun Mountains, so we should pay attention to the danger of the eastern segment of the thrust fault in the front of the West Kunlun Mountains. Most aftershocks are triggered by the main shock. The part of Coulomb gravity increasing in the surrounding area caused by the main shock, and the distribution of aftershock is relatively dense; However, the distribution of aftershocks due to the decrease of Coulomb stress caused by the main shock is relatively sparse. 3) the horizontal plane stress increases in the Qaidam basin in the north of the epicenter of the earthquake and in the northwest of the Qinghai-Xizang Plateau in the south. In the north of Qinghai-Xizang Plateau to the east of the epicenter and the eastern part of Pamir Plateau on the west side of the epicenter, the main compressive stress of the epicentral region is nearly SN from the direction of horizontal principal pressure and claim stress. The direction of the stress is EW, and the principal compressive stress is radiating outward with the epicenter as the center, while the advocate stress is close to the concentric circle with the epicenter as the center. The principal compressive stress in the west side of the epicenter is NW direction, and the eastern side of the epicenter is NE direction. The stress decreases gradually with the increase of radius, the center reaches 107 Pa, and the Maidan fault in the northern part of Chaidabu basin is only at 100 Pa level.
【作者单位】：中国地震局地球物理研究所;防灾科技学院;
【基金】：中央高校基本科研业务费专项资金青年教师资助计划(ZY20130211);中央高校基本科研业务费专项资金创新项目团队资助计划(ZY20110101)共同资助河北省廊坊市科技计划项目(2016011011) 国家自然科学基金(41674055)
【分类号】：P315.727
【正文快照】： 0引言根据中国地震台网中心(http:∥www.ceic.ac.cn/)测定,2015年7月3日当地时间9时7分,新疆维吾尔自治区和田地区皮山县(37.6°N,78.2°E)发生MW6.4地震。震中距皮山县城以西约7km。该地震发生在距印度板块和欧亚板块碰撞带数百km的青藏高原北缘,位于EW向的西昆仑山前断裂附

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