文章基本信息

标题：Micro-slips in an experimental granular shear band replicate the spatiotemporal characteristics of natural earthquakes
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作者：David Houdoux ; Axelle Amon ; David Marsan 等
期刊名称：Communications Earth & Environment
电子版ISSN：2662-4435
出版年度：2021
卷号：2
期号：1
页码：1-11
DOI：10.1038/s43247-021-00147-1
语种：English
出版社：Nature Research
摘要：Memory effects in seismology-such as the occurrence of aftershock sequences-are implicitly assumed to be governed by the time since the main event. However, experiments are yet to identify if memory effects are structural or time-dependent mechanisms. Here, we use laser interferometry to examine the fluctuations of deformation which naturally emerge along an experimental shear fault within a compressed frictional granular medium. We find that deformation occurs as a succession of localized micro-slips distributed along the fault. The associated distributions of released seismic moments, as well as the memory effects in strain fluctuations and the time correlations between successive events, follow exactly the empirical laws of natural earthquakes. We use a methodology initially developed in seismology to reveal at the laboratory scale the underlying causal structure of this behavior and identify the triggering kernel. We propose that strain, not time, controls the memory effects in our fault analog. Deformation experiments using glass beads generate nano-earthquakes that mimic the spatio-temporal pattern of strain in natural seismicity and suggest memory effects associated with strain fluctuations are strain-dependent rather than time-dependent.