Coulomb stress evolution along the Kongur Extensional System since 1895 and present seismic hazard
Coulomb stress evolution along the Kongur Extensional System since 1895 and present seismic hazard
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DOI：
10.1016/j.geog.2018.11.007
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发表时间：
2019-01
影响因子：
2.4
通讯作者：
Wei Xiong;X. Qiao;Gang Liu;Wei Chen;Zhaosheng Nie
中科院分区：
文献类型：
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作者：
Wei Xiong;X. Qiao;Gang Liu;Wei Chen;Zhaosheng Nie
帕米尔高原东北缘现今构造活动主要为东西向伸展，其中孔古尔伸展系（KES）对帕米尔高原的内部扩张起着重要作用。作为自1895年和1896年塔什库尔干地震以来最大的地震，阿克陶地震于2016年发生在KES北方部分的Muji断层上。此后，沿着昆仑山地震活动的趋势一直受到人们的关注。基于粘弹性层状岩石圈模型，计算了1895年以来KES及邻区5次历史地震的同震和震后应力变化，分析了强震间的相互作用。结果表明，1895年以后的历史地震都发生在同震和震后库仑应力增加的地区。1896年塔什库尔干地震、1974年马尔康苏地震和2016年阿克陶地震震源的库仑应力载荷分别为0.251 MPa、0.013 MPa和0.563 MPa。这三次地震都是由这种变化催化的。历史地震使昆盖山南断裂和孔古尔断裂沿着昆仑山东段大部分地段的应力状态增强。特别是，我们可以识别出两个明显的地震空区，其地震危险性增加，形成于KES的齐姆干段和布伦口段。其木干段和布伦口段位于应力集中、伸展速率大的断层过渡带，目前应高度重视其地震危险性。
The present-day tectonic activities on the northeastern margin of the Pamir Plateau are mainly E-W oriented extensions, among which the Kongur Extensional System (KES) plays an important role in the internal expansion of the Pamir. As the largest earthquake since Taxkorgan earthquakes in 1895 and 1896, the Aketao earthquake occurred on the Muji fault on the northern portion of the KES in 2016. Since then, the trend of seismic activities along the KES has been paid much attention to. Based on the visco elastic layered lithosphere model, we calculate the co-seismic and post-seismic stress changes caused by five historical earthquakes on the KES and its adjacent areas since 1895, and analyze the interaction among strong earthquakes. The results show that all of the historical earthquakes after 1895 occurred in the areas where the co-seismic and post-seismic Coulomb stress increased. Coulomb stress loading at the hypocenters of the 1896 Taxkorgan earthquake, the 1974 Markansu earthquake and the 2016 Aketao earthquake were 0.251 MPa, 0.013 MPa and 0.563 MPa, respectively. The three earthquakes were catalyzed by such variations. The historical earthquakes increased the stress state on most segments of the Southern Kungai Mountain fault and Kongur fault along the KES. In particular, we can identify 2 visible earthquake gaps with increasing seismic hazard formed on the Qimugan segment and Bulunkou segment of the KES. The Qimugan section and the Bulunkou section are located at the fault transition zone with concentrated stress and high extension rate, so great attention should be paid to their seismic hazard at present day.