Moisture‐related weakening and strengthening of a fault activated at seismic slip rates
Moisture‐related weakening and strengthening of a fault activated at seismic slip rates
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DOI：
10.1029/2006gl026980
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发表时间：
2006-08
影响因子：
5.2
通讯作者：
K. Mizoguchi;T. Hirose;T. Shimamoto;E. Fukuyama
中科院分区：
文献类型：
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作者：
K. Mizoguchi;T. Hirose;T. Shimamoto;E. Fukuyama
从辉长岩上以85 mm/s的速率进行的高速摩擦实验中，我们发现具有薄断层泥层的断层经历了滑动弱化，摩擦系数下降约80%。在室内湿度条件下，故障随后恢复其完整的强度，在滑动终止后的几分钟内。在干燥的N2气体饱和条件下不发生强度恢复。这一结果可以解释为水分与凿痕颗粒的相互作用：由于摩擦加热而导致水分流失弱化，由于冷却而导致水分吸收强化。这种新的机制可以导致断层的动力弱化，从而控制地震破裂的传播。
From high‐velocity friction experiments on gabbro rock at a rate of 85 mm/s, we found that a fault with a thin gouge layer experienced slip weakening with a drop of about 80% in the friction coefficient. At room humidity conditions, the fault subsequently recovered its complete strength, over an interval of several minutes after the slip terminated. The strength recovery did not occur under dry N2 gas‐saturated condition. This result can be interpreted as the interaction of moisture with gouge particles: moisture‐drained weakening due to frictional heating and moisture‐absorbed strengthening due to cooling. This new mechanism can cause dynamic weakening of faults, which controls earthquake rupture propagation.