Effects of Humidity, Shear Stress, and Strain Rate Localization on Fault Healing and Friction

地震周期要求断层在地震之间重新加强。摩擦愈合（如在准静态接触期间增加静摩擦所证明的）被认为是最可能的震间强度恢复机制。然而，摩擦愈合的机制知之甚少。本研究拟在模拟粒状断层泥中研究断层愈合和摩擦老化的物理化学机制。实验的结果将有显着的影响，了解时间和滑动相关的摩擦演化之间的区别。动态破裂的最新理论研究表明，这种区别在确定地震特征方面起着关键作用，例如频率-震级标度和破裂扩展模式（作为经典的自相似裂纹或自愈滑动脉冲）。因此，其结果将以一种重要的方式连接到震源物理学的其他研究，包括基于理论的研究和基于现场观测的研究。

Marone EAR-0001215 The seismic cycle requires that faults re-strengthen between earthquakes. Frictional healing (as evidenced by increasing static friction during quasi-stationary contact) is considered the most likely mechanism of interseismic strength recovery. However, the mechanisms of frictional healing are poorly understood. This proposal is to study the physical and chemical mechanisms of fault healing and frictional aging in simulated granular fault gouge. The results of the experiments will have significant implications for understanding the distinction between time- and slip-dependent friction evolution. Recent theoretical studies of dynamic rupture indicate that this distinction plays a key role in determining seismic characteristics such as frequency-magnitude scaling and the mode of rupture expansion (as a classical, self-similar crack or a self-healing slip pulse). Thus, the results will connect in an important way to other studies of earthquake source physics including theoretically-based studies and those based on field observations.