Statistical similarity between the compression of a porous material and   earthquakes
  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. 
Jordi Baro, Alvaro Corral, Xavier Illa, Antoni Planes, Ekhard K. H.   Salje, Wilfried Schranz, Daniel E. Soto-Parra, and Edu...
physics.geo-ph cond-mat.mtrl-sci nlin.AO