Toward a universal framework for avalanche dynamics: From crystal slip to fault slip

Sudden bursts of energy release, commonly referred to as “avalanches”, are ubiquitous in many complex systems, from seismic activities in the Earth’s crust to microscale dislocation activities in crystal lattices. Despite the massive differences in the underlying energy release mechanisms and their time and length scales, these events often display remarkable similarities, hinting at shared governing principles. In this study, we establish a direct analogy between dislocation avalanches in single-crystal nickel and seismic activity by combining in situ microcompression experiments with high-resolution acoustic emissions (AE) measurements. By correlating abrupt strain bursts with the spectral and temporal characteristics of AE signals, we introduce a new framework to identify “mainshock”-like events during dislocation avalanches and correlate them with their foreshocks and aftershocks. Our results show that the intermittent, scale-free dynamics of dislocation avalanches mirror earthquake statistics, including the Gutenberg–Richter, Omori, and Båth laws, providing phenomenological rules that describe energy release and event clustering in dislocation avalanches. This reflects the universality of these laws across widely different length and time scales and material systems. Additionally, while the overall avalanche statistics remain independent of the micropillar diameter, the magnitude of AE signals and load drops exhibits a strong size dependence. Overall, these findings increase our understanding of the fundamental mechanisms that govern plasticity and underscore the robust analogy between dislocation-mediated deformation and seismic processes.