Is stress accumulating on the creeping section of the San Andreas fault?
Is stress accumulating on the creeping section of the San Andreas fault?
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圣安德烈亚斯断层的蠕动部分是否正在积累应力？
DOI：
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
K. Johnson
中科院分区：
文献类型：
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作者：
K. Johnson
位于加州中部的圣安德烈亚斯断层（CSAF）的蠕动段是一个被认为是大地震传播的障碍。然而，最近的研究表明，蠕动段并不是完全不耦合的，而是以相当于每150年发生一次Mw=7.2-7.4地震的速度积累滑动亏损。了解CSAF地震潜力的一个关键部分是确定滑动赤字是否发生在粘滑区域上的应力积累或在周围锁定区域阴影下的稳定滑动区域上没有应力积累。我们使用一个物理模型来估计锁定的空间分布，由表面蠕变率测量和GPS的派生速度的限制，断层的应力累积区。我们发现，断层累积应力区，如果每150年破裂一次，最多释放相当于一次Mw=6.75地震的滑动，明显小于Mw=7.2-7.4的150年等效总滑动亏损率。
The creeping section of the San Andreas fault (CSAF) in central California is a proposed barrier to propagation of large earthquakes. Yet, recent studies show that the creeping section is not entirely uncoupled but is accumulating slip deficit at a rate equivalent to a Mw=7.2–7.4 earthquake every 150years. A critical piece to understanding earthquake potential on the CSAF is determining whether slip deficit is occurring with stress accumulation on stick‒slip regions or without stress accumulation on stable‒sliding regions shadowed by surrounding locked areas. We use a physical model to estimate the spatial distribution of locked, stress‒accumulating areas of the fault constrained by surface creep rate measurements and GPS‒derived velocities. We find that the area of the fault accumulating stress, if ruptured every 150years, would release slip equivalent to at most a Mw=6.75 earthquake, significantly less than the Mw=7.2–7.4, 150year equivalent total slip deficit rate.