[S-CG69] Rheology, fracture and friction in Earth and planetary sciences

[SCG69-P07] Continuously sheared granular matter reproduces in detail seismicity laws

*Victor Simon Levy dit Vehel¹, Sebastien Lherminier, Ramon Planet³, Gilles Simon¹, Knut Jørgen Måløy², Loic Vanel¹, Osvanny Ramos¹ (1.Institut Lumiere Matiere Lyon 1, 2.University of Oslo, 3.University of Barcelona)

Keywords:Earthquake, Shearing, Granular matter, Dilation

Earthquake forecast has long been an objective for geoscience, resisting scientific efforts for more than a century. This difficulty stems in part from the very large spectrum of time and energy scales, a feature required of physics-earthquake analogies [1], as well as the complexity of the system producing earthquakes. Efforts to model this phenomenon might aim to reduce the complexity of the mechanisms while preserving the richness of the dynamics. Simple model have been proposed (friction of blocs, granular shearing) with some success over the years, replicating a few features of earthquakes. We propose a continuously sheared granular experiment [1] that marginally increase system complexity (in regard to prior experiments) while achieving quantitative agreements with several key features of earthquake statistics (Gutenberg-Richter law, Omori law, inter-event time distribution [2]). Furthermore, recent upgrades in our setup allows us to track every grain and contact force (through photo-elasticity) as well as the global dilation of the granular medium [3]. We welcome any insight or discussion about analysis and interpretation of the vast amounts of data produced by our experiment.

[1] S. Lherminier, R. Planet, V. Levy dit vehel, G. Simon, K. J. Måløy, L. Vanel & O.Ramos : Continuously sheared granular matter reproduces in detail seismicity laws, Phys. Rev. Lett. 122, 218501 (2019)

[2] A Corral : Long-term clustering, scaling, and universality in the temporal occurrence of earthquakes, Phys. Rev. Lett. 92, 108501 (2004)

[3] V. Levy dit Vehel, F. Dubourg, L. Vanel, K. J. Måløy, & O.Ramos : Evolution of the distance between plates in an experimental granular fault. Implications for earthquake forecast, RNL 2018 proceedings (2018)