Constraining Fault Friction and Stability With Fluid‐Injection Field Experiments
Constraining Fault Friction and Stability With Fluid‐Injection Field Experiments
复制标题
通过流体注入现场实验约束断层摩擦和稳定性
DOI：
10.1029/2020gl091188
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发表时间：
2021
影响因子：
5.2
通讯作者：
Cappa, Frédéric
中科院分区：
文献类型：
--
作者：
Larochelle, Stacy;Lapusta, Nadia;Ampuero, Jean‐Paul;Cappa, Frédéric
虽然将流体注入地下可以通过减少摩擦阻力来重新激活断层的概念已经得到了很好的确立，但对随后的滑动演化仍然知之甚少。是什么控制了诱发的滑动是否保持稳定并限制在流体影响区或加速成为失控的地震？在地震发生之前，是否有可观察到的地震倾向指标？在这里，我们研究这些问题，通过模拟一个独特的流体注入实验的自然断层与实验室推导的摩擦定律。我们表明，一系列的故障模型与发散稳定性与持续注入重现在加压过程中测得的滑移。然而，在减压时，最不稳定的情况与观测结果不同，这表明断层相对稳定。模型可以进一步区分优化降压试验或空间分布监测。我们的研究结果表明，避免在低剩余摩擦断层附近注入，并在滑动加速期间减压，可以帮助防止大规模地震。
While the notion that injecting fluids into the subsurface can reactivate faults by reducing frictional resistance is well established, the ensuing evolution of the slip is still poorly understood. What controls whether the induced slip remains stable and confined to the fluid‐affected zone or accelerates into a runaway earthquake? Are there observable indicators of the propensity to earthquakes before they happen? Here, we investigate these questions by modeling a unique fluid‐injection experiment on a natural fault with laboratory‐derived friction laws. We show that a range of fault models with diverging stability with sustained injection reproduce the slip measured during pressurization. Upon depressurization, however, the most unstable scenario departs from the observations, suggesting that the fault is relatively stable. The models could be further distinguished with optimized depressurization tests or spatially distributed monitoring. Our findings indicate that avoiding injection near low‐residual‐friction faults and depressurizing during slip acceleration could help prevent large‐scale earthquakes.