Dynamic modeling of slow slip coupled with tremor
Dynamic modeling of slow slip coupled with tremor
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慢滑移与颤动耦合的动力学建模
DOI：
10.1029/2010jb008136
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
T. and T. Suzuki
中科院分区：
文献类型：
--
作者：
Yamashita;T. and T. Suzuki
我们从理论上研究了假设流体饱和热多孔弹性介质中存在断层的动力学框架中慢滑移的产生机制；考虑了流体流动。假设动态滑移会产生孔隙并导致断层上的剪切加热。建模中的关键参数是Su和Su′。无量纲参数Sure表示孔隙形成对流体压力变化的影响相对于剪切加热的影响的相对主导地位，而Su'则与流体流动效应相对于剪切加热的影响的主导地位相关。我们的计算表明，我们必须假设 Su≫ 1 和相对较小的 Su′ 值来模拟与剪切波速度相比小到可以忽略不计的破裂速度。虽然我们之前的论文中也发现了这一点，但我们在这里的新发现是模拟慢滑移与颤动相结合。我们发现冻结滑移偶尔会重新激活，因为孔隙形成引发的流体流入提高了断层上的流体压力。如果Su'小于阈值，则滑动重新激活实际上发生。这种零星的滑移重新激活可以作为缓慢滑移与震颤相结合的模型。我们还表明，当 Su′ < 0.1 时，矩演化曲线分为两组：一组代表慢滑移，另一组代表普通地震。
We theoretically study the generation mechanism of slow slip in a dynamical framework assuming a fault in a fluid‐saturated thermoporoelastic medium; the fluid flow is taken into consideration. Dynamic slip is assumed to create pores and cause shear heating on the fault. Key parameters in the modeling areSuandSu′. The nondimensional parameterSurepresents the relative dominance of the effect of pore creation on the fluid pressure change over that of shear heating, whileSu′ is associated with the dominance of fluid flow effect over the effect of shear heating. Our calculation shows that we have to assumeSu≫ 1 and relatively small values forSu′ to simulate rupture speed that is negligibly small compared to the shear wave velocity. Although this was also found in our former paper, our new finding here is the simulation of slow slip coupled with tremor. We find that frozen slip is reactivated sporadically because the fluid inflow triggered by the pore creation elevates the fluid pressure on the fault. The slip reactivation actually occurs ifSu′ is smaller than a threshold. Such sporadic reactivation of slips can be a model for slow slip coupled with tremor. We also show that the moment evolution curves are categorized into two separate groups whenSu′ ≪ 0.1: one of them represents slow slips, while the other represents ordinary earthquakes.