Preliminary Study of Fault Rupture Scale of the 2017 Jiuzhaigou MS 7.0 Earthquake
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摘要: 本文利用2017年九寨沟7.0级地震的余震序列数据,结合震源机制解确定的地震断层面,研究了地震断层的破裂尺度。基于余震序列在断层面上的投影,分析直接余震和间接余震以及不同起始震级条件下余震区的长度和震源深度分布,估算了地震断层破裂面的破裂长度和破裂深度,并探讨了地震断层破裂对地震烈度分布的影响。研究结果显示,九寨沟7.0级地震断层的破裂长度约33—35km,破裂深度约23—26km;地震断层破裂对Ⅷ度区分布有明显的控制作用,地震断层破裂长度接近Ⅷ度区的长度。Abstract: Using the aftershock sequence data of the Jiuzhaigou MS 7.0 earthquake in 2017 and the earthquake fault plane determined by the focal mechanism solution, the rupture scale of the earthquake fault was studied. Based on the projection of the aftershock sequence on the fault plane, the distribution of the length and focal depth of the aftershock zones under different initial magnitude conditions is analyzed for the direct and indirect aftershocks, the rupture length and rupture depth of the fault plane of the earthquake were estimated. Finally, the influence of earthquake fault rupture on the distribution of earthquake damage was discussed. The results show that the rupture length of Jiuzhaigou earthquake is about 33-35km, and the rupture depth is estimated to be 23-26km. The rupture of earthquake fault has significant control over the distribution of the Ⅷ degree zone, and the rupture length of the earthquake is close to the length of the Ⅷ degree zone.
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Key words:
- The Jiuzhaigou earthquake /
- Earthquake fault /
- Rupture scale /
- Aftershock sequence
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表 1 九寨沟7.0级地震震源机制解参数
Table 1. Parameters of focal mechanism solution of the Jiuzhaigou MS 7.0 earthquake
来源 MW 震源深度/km 节面Ⅰ/° 节面Ⅱ/° 走向 倾角 滑动角 走向 倾角 滑动角 CENC 6.5 11 326 62 -15 64 77 -151 CGMT 6.5 16.2 151 79 -8 243 82 -168 -
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