九寨沟Ms 7.0级地震的左旋走滑作用与动力机制

发布时间：2018-03-30 19:45

本文选题：青藏高原东缘　切入点：九寨沟地震　出处：《成都理工大学学报(自然科学版)》2017年06期

【摘要】：2017年8月8日四川九寨沟发生的Ms 7.0级地震是继2008年汶川Ms 8.0地震、2013年芦山Ms 7.0级地震后在青藏高原东缘发生的又一次强震。本文通过综合分析九寨沟Ms 7.0级地震及历史地震的震源机制解、余震和历史地震分布、区域应力场、活动断层等资料,来揭示九寨沟地震的发震构造与动力机制。初步研究结果表明:(1)此次地震的震中位于塔藏断裂、岷江断裂和虎牙断裂之间的交汇区,显示活动断裂的交汇区对此次地震的发生具有控制作用;(2)发震断裂为虎牙断裂,断裂走向为北西西向,倾向南西,倾角较陡,属于高倾角左旋走滑型地震;(3)震中位于虎牙断裂北段的北部地震空区,充填了1973年和1976年4次大于Mw6.0级地震空区;(4)此次地震位于2008年汶川Ms 8.0级地震的库仑应力增加区,应是汶川地震的应力传递和触发的结果;(5)此次地震位于巴颜喀拉块体的东北部顶角区,青藏高原东缘下地壳流向北东方向的挤出是驱动此次地震的动力机制。
[Abstract]:The Ms 7.0 earthquake in Jiuzhaigou, Sichuan Province on August 8, 2017 was another strong earthquake on the eastern edge of the Qinghai-Tibet Plateau following the 2008 Wenchuan Ms 8.0 earthquake and the 2013 Lushan Ms 7.0 earthquake.In this paper, the seismogenic structure and dynamic mechanism of Jiuzhaigou earthquake are revealed by synthetically analyzing the focal mechanism solution, aftershock and historical earthquake distribution, regional stress field and active fault of Jiuzhaigou earthquake with Ms 7.0 and historical earthquake.The preliminary results show that the epicenter of the earthquake is located in the intersection area between the Ta-Zang fault, the Minjiang fault and the Hu-ya fault, indicating that the intersection area of the active fault has a controlling effect on the occurrence of the earthquake.) the seismogenic fault is the Hu-ya fault.The fault strike is NW-trending, trending southwestward, and the dip angle is steep, which belongs to the high-dip left-lateral strike-slip earthquake No. 3) the epicenter of which is located in the northern seismic void area of the northern segment of the Hu-ya fault.This earthquake is located in the Coulomb stress increase area of the 2008 Wenchuan Ms 8.0 earthquake.It should be the result of stress transfer and trigger of Wenchuan earthquake. The earthquake is located in the northeast corner of Bayan Kara block. The extrusion of the lower crust in the eastern margin of Qinghai-Xizang Plateau is the dynamic mechanism driving the earthquake.
【作者单位】：油气藏地质及开发工程国家重点实验室(成都理工大学);四川省蜀通岩土工程公司;四川省地震局;华蓥市地质环境监测站;
【基金】：国家自然科学基金项目(40841010,40972083,41172162,41372114,41340005) 国土资源部地质调查项目(1212011121268) 油气藏地质及开发工程国家重点实验室研究项目(SK-0801)
【分类号】：P315

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