Theoretical studies predict that during earthquake rupture faults slide at non-constant slip velocity, however it is not clear which source time functions are compatible with the high velocity rheology of earthquake faults. Here we present results from high velocity friction experiments with non-constant velocity history, employing a well-known seismic source solution compatible with earthquake source kinematics. The evolution of friction in experiments shows a strong dependence on the applied slip history, and parameters relevant to the energetics of faulting scale with the impulsiveness of the applied slip function. When comparing constitutive models of strength against our experimental results we demonstrate that the evolution of fault strength is directly controlled by the temperature evolution on and off the fault. Flash heating predicts weakening behavior at short timescales, but at larger timescales strength is better predicted by a viscous creep rheology. We use a steady-state slip pulse to test the compatibility of our strength measurements at imposed slip rate history with the stress predicted from elastodynamic equilibrium. Whilst some compatibility is observed, the strength evolution indicates that slip acceleration and deceleration might be more rapid than that imposed in our experiments.

中文翻译：

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模拟地震滑动脉冲期间的故障摩擦

理论研究预测，在地震破裂期间，断层以非恒定滑动速度滑动，但尚不清楚哪些源时间函数与地震断层的高速流变学兼容。在这里，我们展示了具有非等速历史的高速摩擦实验的结果，采用了与震源运动学兼容的著名震源解决方案。实验中摩擦的演变显示出强烈依赖于应用的滑移历史，以及与断层尺度能量学相关的参数以及应用滑移函数的冲动性。当将强度本构模型与我们的实验结果进行比较时，我们证明断层强度的演变直接受断层内外温度演变的控制。快速加热可预测短时间范围内的弱化行为，但在较大时间范围内，粘性蠕变流变学可以更好地预测强度。我们使用稳态滑移脉冲来测试我们在施加的滑移率历史记录下的强度测量与从弹性动力学平衡预测的应力的兼容性。虽然观察到一些兼容性，但强度演变表明滑动加速和减速可能比我们的实验中强加的更快。