Earthquakes are the dynamic rupture of faults governed by fault weakening processes. Critical slip-weakening distance () is a crucial source parameter of earthquakes, and the determination of is of great concern to semiologists. However, determining for natural earthquakes is challenging due to the trade-off in inversed source models. To solve this problem, Fukuyama and his coworkers proposed a simple method (denoted as the F&M method) to estimate directly from slip-velocity functions. According to the F&M method, the fault slip at the peak slip velocity (') can be used as an approximation of . However, the feasibility of this method has not been completely resolved. Here, we performed laboratory earthquake rupture experiments to examine the validity of the F&M method. Experiments were conducted on faults with different roughness and stress level. We studied the effect of fault roughness on the validity of the F&M method. Our results show that the increase in fault roughness could complicate the fault weakening process, producing repeated weakening and strengthening phase, which leads to a prominent deviation between ' and . Furthermore, we also observed a correlation between the critical slip-weakening distance and the final fault slip . Such correlation implies the scale-dependent nature of , which is consistent with seismic observations in the field.

中文翻译：

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断层粗糙度对根据断层滑动历史估计临界滑动弱化距离的影响：实验室研究


地震是受断层弱化过程控制的断层动态破裂。临界滑移弱化距离（）是地震的重要震源参数，其确定一直是符号学家非常关心的问题。然而，由于反演震源模型的权衡，确定自然地震具有挑战性。为了解决这个问题，福山和他的同事提出了一种直接根据滑移速度函数进行估计的简单方法（称为 F&M 方法）。根据 F&M 方法，峰值滑移速度 (') 处的断层滑移可用作 的近似值。但该方法的可行性尚未完全解决。在这里，我们进行了实验室地震破裂实验来检验 F&M 方法的有效性。对不同粗糙度和应力水平的断层进行了实验。我们研究了断层粗糙度对 F&M 方法有效性的影响。我们的结果表明，断层粗糙度的增加会使断层弱化过程复杂化，产生反复的弱化和强化阶段，从而导致 和 之间存在显着的偏差。此外，我们还观察到临界滑移减弱距离与最终断层滑移之间的相关性。这种相关性意味着 的尺度依赖性，这与现场地震观测结果一致。