Impoundment of the Zipingpu reservoir and triggering of the 2008 Mw 7.9 Wenchuan earthquake, China
Impoundment of the Zipingpu reservoir and triggering of the 2008 Mw 7.9 Wenchuan earthquake, China
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紫坪铺水库蓄水引发2008年中国汶川7.9级地震
DOI：
10.1002/2014jb011766
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发表时间：
2015-10
影响因子：
--
通讯作者：
Erika Ronchin
中科院分区：
文献类型：
--
作者：
Wei Tao;Timothy Masterlark;Zheng-Kang Shen;Erika Ronchin
紫坪铺水库中国水库于2005年9月蓄水，2.7年后，2008年汶川7.9级地震导致龙门山断裂破裂，震中距紫坪铺水库约12公里。基于孔弹性理论，采用三维有限元模型模拟了水库蓄水引起的应力和孔压的演化过程及其对库仑破坏应力的影响。结果表明，水库蓄水形成了一个孔隙压力锋，随着流体的扩散缓慢地在地壳中传播。在WE之前，水库荷载导致震源库仑破坏应力适度增加或没有增加。而在LSF上，库仑破裂应力在1-8公里的深度范围内增长了约9.3-69.1kPa，可能将断裂系统的构造载荷提前了约60-450年。由于断层几何形状和震中位置的不确定性，ZR的蓄水是否直接触发了WE尚无定论。然而，震中的一个小事件可能会在断层上的其他地方引发大破裂，那里的凹凸体被ZR削弱了。ZR周围的微震活动也显示出自ZR蓄水以来的扩张模式，可能与正孔隙压力脉冲的扩散有关。这些结果表明，由于ZR的蓄水，WE具有孔弹性触发效应(即使是间接的)。
Impoundment of the Zipingpu reservoir (ZR), China, began in September 2005 and was followed 2.7 years later by the 2008 Mw 7.9 Wenchuan earthquake (WE) rupturing the Longmen Shan Fault (LSF), with its epicenter ~12 km away from the ZR. Based on the poroelastic theory, we employ three‐dimensional finite element models to simulate the evolution of stress and pore pressure due to reservoir impoundment, and its effect on the Coulomb failure stress on the LSF. The results indicate that the reservoir impoundment formed a pore pressure front that slowly propagated through the crust with fluid diffusion. The reservoir loading induced either moderate or no increase of the Coulomb failure stress at the hypocenter prior to the WE. The Coulomb failure stress, however, grew ~9.3–69.1 kPa in the depth range of 1–8 km on the LSF, which may have advanced tectonic loading of the fault system by ~60–450 years. Due to uncertainties of fault geometry and hypocenter location of the WE, it is inconclusive whether impoundment of the ZR directly triggered the WE. However, a small event at the hypocenter could have triggered large rupture elsewhere on fault, where the asperities were weakened by the ZR. The microseismicity around the ZR also showed an expanding pattern from the ZR since its impoundment, likely associated with diffusion of a positive pore pressure pulse. These results suggest a poroelastic triggering effect (even if indirectly) of the WE due to the impoundment of the ZR.
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DOI：
--
发表时间：
2009
期刊：
Chinese Journal of Geophysics
影响因子：
--
作者：
Cheng Jiu
通讯作者：
Cheng Jiu
DOI：
--
发表时间：
--
期刊：
The FEBS Journal
影响因子：
--
作者：
通讯作者：
--
影响因子：
2
作者：
P. Talwani
通讯作者：
P. Talwani
影响因子：
3
作者：
Li Yan’e
通讯作者：
Li Yan’e
影响因子：
3
作者：
Shiyong Zhou;Kai Deng
通讯作者：
Shiyong Zhou;Kai Deng