Regularity and complexity of aftershock occurrence due to mechanical interactions between fault slip and fluid flow
Regularity and complexity of aftershock occurrence due to mechanical interactions between fault slip and fluid flow
复制标题
断层滑移与流体流动的机械相互作用导致余震发生的规律性和复杂性
DOI：
10.1046/j.1365-246x.2003.01790.x
复制
发表时间：
2003
影响因子：
2.8
通讯作者：
T. Yamashita
中科院分区：
文献类型：
--
作者：
T. Yamashita
摘要假设流体在半无限弹性介质中沿着垂直走滑断层形成的狭窄、多孔断层带中的流体迁移，对一系列余震进行了模拟。有效应力与库仑破坏准则的耦合原理引入了断层滑动与孔隙流体之间的力学耦合。假设在主震发生的瞬间，流体从断裂带的局部高压流体隔间流出。我们成功地用统一的方法模拟了观测到的余震的规律性和复杂性。例如，我们可以模拟Omori定律和Gutenberg-Richter关系，这是地震学观测到的最突出的规律性。大多数模拟的余震都是由反复滑动组成的，即在余震序列中较早经历过滑动的断层段上的滑动。我们的计算表明，古登堡-里希特关系的出现与这些反复滑移的发生密切相关。复杂性也是余震的一个显著特征。其中一个例子是次生余震的发生，如果我们假设在一个断裂带上形成几个高压流体包体或破裂引起渗透率的显著变化，也可以成功地模拟次生余震。
SUMMARY A sequence of aftershocks is modelled assuming fluid migration in a narrow, porous fault zone formed along a vertical strike-slip fault in a semi-infinite elastic medium. The principle of the effective stress coupled to the Coulomb failure criterion introduces mechanical coupling between fault slip and pore fluid. The fluid is assumed to flow out of localized high-pressure fluid compartments in the fault zone at the instant of the main shock occurrence. We successfully simulate both regularity and complexity observed for aftershocks in a unified way. For example, we can simulate both the Omori law and the Gutenberg‐Richter relation, which are the most outstanding regularity observed seismologically. A large majority of simulated aftershocks are shown to consist of repeated slips, that is, slips on fault segments that have experienced slips earlier in the aftershock sequence. Our calculations show that the emergence of the Gutenberg‐ Richter relation is closely related to the occurrence of these repeated slips. Complexity is also a striking feature of aftershocks. One of the examples is the occurrence of secondary aftershocks, which can also be simulated successfully if we assume several high-pressure fluid compartments formed in a fault zone or a significant change in the permeability caused by the rupture occurrence.
影响因子：
3
作者：
Y. Okada
通讯作者：
Y. Okada