Quasi‐static fault slip on an interface between poroelastic media with different hydraulic diffusivity: A generation mechanism of afterslip
Quasi‐static fault slip on an interface between poroelastic media with different hydraulic diffusivity: A generation mechanism of afterslip
复制标题
不同水力扩散率多孔弹性介质界面上的准静态断层滑动：后滑的产生机制
DOI：
10.1029/2008jb005930
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发表时间：
2009
影响因子：
--
通讯作者：
Takehito Suzuki
中科院分区：
文献类型：
--
作者：
T. Yamashita;Takehito Suzuki
[1] 我们从理论上研究了后滑的产生机制，假设双材料界面上存在二维面内断层，该断层分隔具有不同水力扩散系数的多孔弹性半空间；假设变形是准静态的。我们的研究表明，由于不断演变的断层滑动和流体压力积聚之间的正反馈，同震断层活动有效地触发了准静态断层尖端生长。 Yamashita (2007) 也进行了类似的研究，但他假设差异仅在于 Biot-Willis 系数以及不排水和排水泊松比。与Yamashita(2007)模型的比较表明，扩散对比对于后滑流的产生更为有效。我们还发现，在扩散率较高的介质中，断层尖端很可能沿滑移方向单侧延伸；扩散率对比越大，断层生长的持续时间越长。我们发现了一种标度关系，其中准静态断层延伸释放的力矩可以通过断层增长持续时间的线性函数来很好地近似。这与二维经典动态故障模型的预期有很大不同；如果假设经典断层模型，则力矩与断层增长持续时间的平方成正比。
[1] We theoretically study the generation mechanism of afterslip, assuming a two-dimensional in-plane fault on a bimaterial interface that separates poroelastic half-spaces with different hydraulic diffusivities; the deformation is assumed to be quasi-static. Our study shows that the coseismic faulting triggers quasi-static fault tip growth effectively because of positive feedback between the evolving fault slip and fluid pressure buildup. A similar study was made by Yamashita (2007), but he assumed the difference to be only in the Biot-Willis coefficient and undrained and drained Poisson's ratios. A comparison with the model of Yamashita (2007) shows that the diffusivity contrast is much more effective for the generation of afterslip. We also find that the fault tip is likely to extend unilaterally in the direction of slip in the medium of higher diffusivity; the duration of fault growth is longer for a larger diffusivity contrast. We find a scaling relationship in which the moment released by the quasi-static fault extension is approximated well by a linear function of the duration of fault growth. This is largely different from the expectations from a 2-D classical dynamic fault model; the moment is proportional to the square of duration of fault growth if the classical fault model is assumed.
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通讯作者：
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影响因子：
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作者：
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影响因子：
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DOI：
--
发表时间：
2003
期刊：
Geophys. Res. Lett. 30
影响因子：
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作者：
Y.Yagi;M.Kikuchi;T.Nishimura
通讯作者：
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DOI：
--
发表时间：
2005
期刊：
Butsuri-tansa(Geophysical Exploration) 58
影响因子：
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作者：
Kimura;T
通讯作者：
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