Statistical similarity between the compression of a porous material and earthquakes

TL;DR

This study demonstrates that acoustic emissions during Vycor compression follow seismic laws like Gutenberg-Richter and Omori's law, revealing deep statistical similarities between material fracture and earthquakes across multiple decades.

Contribution

It provides a comprehensive statistical characterization of fracture events in porous materials, establishing strong parallels with earthquake phenomena and extending understanding of fracture dynamics.

Findings

Gutenberg-Richter law applies over five decades

Omori's law holds independently of compression rate

Waiting-time distribution follows a power-law with exponent ~2.45

Abstract

It has been long stated that there are profound analogies between fracture experiments and earthquakes; however, few works attempt a complete characterization of the parallelisms between these so separate phenomena. We study the Acoustic Emission events produced during the compression of Vycor (SiO2). The Gutenberg-Richter law, the modified Omori's law, and the law of aftershock productivity are found to hold for a minimum of 5 decades, are independent of the compression rate, and keep stationary for all the duration of the experiments. The waiting-time distribution fulfills a unified scaling law with a power-law exponent close to 2.45 for long times, which is explained in terms of the temporal variations of the activity rate.