近日，法国蔚蓝海岸大学Fryer, Barnaby团队报道了前震诱发的滑移瞬态决定主震成核时间。2026年5月6日出版的《自然》杂志发表了这项成果。

地震前有时会观测到前震，但其在控制破裂成核中的作用仍不清楚。经典模型通常假设成核源于主要受断层弱化控制的缓慢准静态滑移，通常忽略瞬态前兆事件。

研究组通过实验室实验以及一个基于速率与状态依赖的类格里菲斯破裂框架，表明前震如果在成核起始或过程中发生，能够从根本上调控地震的起始过程。他们发现，前震引发的滑移瞬态产生了一个瞬态滑动速度 Vmin，其大小由前震规模决定，并且能够稳健地预测成核持续时间与空间长度。较大的前震产生更高的Vmin，并触发更快的动态破裂转变；而较小的前震则导致长时间的准静态增长；极小的脉冲则使破裂完全停止。

将该理论框架拓展至构造断层，研究组发现天然地震前的震前震及伴随的慢滑移序列似乎遵循相同的标度关系。这些观测使人们能够约束出实际的特征成核滑移距离为0.3–3.0毫米，比以往动态破裂推断的值小几个数量级。该结果表明，前震诱发的瞬态过程决定了地震成核的时间及其可探测性。

附：英文原文

Title: Foreshock-induced slip transients set mainshock nucleation timing

Author: Fryer, Barnaby, Garagash, Dmitry, Lebihain, Mathias, Passelgue, Franois

Issue&Volume: 2026-05-06

Abstract: Foreshocks are sometimes observed before earthquakes1,2,3,4,5,6,7,8,9,10,11,12,13, yet their role in controlling rupture nucleation remains unclear1,11,14. Classical models often assume that nucleation arises from slow, quasi-static slip governed primarily by fault weakening15,16,17,18,19,20,21, typically neglecting impulsive precursory events. Here we show, using laboratory experiments and a rate-and-state-based Griffith-like rupture framework22, that foreshocks, when they occur at the onset of or during nucleation, can fundamentally regulate earthquake initiation. We find that the slip burst induced by foreshocks imparts a transient sliding velocity, Vmin, whose magnitude is set by foreshock size and which robustly predicts both nucleation duration and spatial length. Larger foreshocks generate higher Vmin and trigger a more rapid transition to dynamic rupture, whereas smaller foreshocks produce long-duration quasi-static growth and very small impulses lead to ruptures entirely arresting. Extending our theoretical framework to tectonic faults, we show that foreshock and associated slow-slip sequences preceding natural earthquakes seem to follow the same scaling. These observations allow us to constrain realistic characteristic nucleation slip distances of 0.3–3.0mm, orders of magnitude smaller than those inferred for dynamic rupture23. Our results demonstrate that foreshock-induced transients set the timing and potential detectability of earthquake nucleation24.

DOI: 10.1038/s41586-026-10497-5

Source: https://www.nature.com/articles/s41586-026-10497-5