AI 中文总结
本文通过大量实验室地震实验，在多参数范围内证实了二维摩擦滑动脉冲理论的预测，明确了脉冲的非稳态特性及衰减到增长的转变，深化了对主导地震破裂模式的认识。
AI 中文摘要
大型天然地震通常由摩擦类脉冲型破裂介导，其特征是存在有限的滑动区域。近期，一种全面的二维摩擦滑动脉冲理论被提出，该理论预测脉冲是绝对不稳定的破裂模式，其演化本质上是缓慢的；非稳态脉冲满足以离散可观测量表示的运动方程，该方程与其稳态对应物存在内在关联，还预测存在从衰减脉冲到缓慢增长脉冲的转变。本文开展大量实验室地震实验以验证该理论，实验在一系列预应力水平、破裂成核条件及小尺度断层粗糙度振幅范围内，证实了类脉冲型实验室地震的理论预测；具体而言，在由演化的脉冲尺寸和峰值滑动速率构成的平面中测试了预测的时间相关动力学，结合对脉冲无量纲增长率的测量，证明了其固有的缓慢非稳态特性；实验还证实了衰减脉冲与增长脉冲之间的预测转变。这些结果为理解主导地震破裂模式取得了重大进展。
英文摘要
Large natural earthquakes are typically mediated by frictional pulse-like rupture, which features a finite slipping zone. Recently, a comprehensive two-dimensional theory of frictional slip pulses has been developed. It predicts that pulses are categorically unstable rupture modes, whose evolution is intrinsically slow. Unsteady pulses satisfy an equation of motion expressed in terms of discrete observables, which is inherently related to their steady-state counterparts. The theory also predicts a transition from decaying to slowly growing pulses. Here, we perform extensive lab earthquake experiments to test the theory. The experiments confirm the theoretical predictions for pulse-like lab earthquakes over a range of prestress levels, rupture nucleation conditions and small-scale fault roughness amplitudes. Specifically, the predicted time-dependent dynamics are tested in a plane defined by the evolving pulse size and peak slip rate, along with measurements of the dimensionless growth rate of pulses, demonstrating their intrinsically slow unsteady nature. The predicted transition between decaying and growing pulses is also experimentally demonstrated. These results constitute major progress in understanding a dominant earthquake rupture mode.
