Logos LIMSI & FAST

Séminaire de Mécanique d'Orsay

Le Jeudi 6 février 2020 à 14h00 - Salle des séminaires FAST-LPTMS (Bât. 530, salle C.120, 1ER)

Towards reliable analogue experiments of earthquakes

Osvanny Ramos
ILM-Lyon

Finding reliable model experiments capable of properly simplifying the huge complexity of earthquakes is maybe the only way to capture the essential ingredients of their dynamics; and a considerable number of experiments have tried to follow this path, by mimicking the behaviour of earthquakes. Two main complementary approaches coexist, either focusing on isolated events or centring the analysis on the statistical behaviour.
I will first introduce them with some examples, before converging on some open questions, historical issues and challenges related to the second approach. Our experimental system will be then introduced. It consists in a monolayer of compressed photoelastic grains that are slowly and continuously sheared. In response, it delivers sudden energy release events that follow quantitatively the main phenomenological relations describing seismicity: Gutenberg-Richter law, Omori law and the inter-event time distribution [1]. The details and implications of these results and the question we are currently tackling with our system will be discussed.
[1] S. Lherminier, R. Planet, V. Levy dit Vehel, G. Simon, K. J. Måløy, L. Vanel and O. Ramos, Continuously sheared granular matter reproduces in detail seismicity laws, Phys. Rev. Lett. 122, 218501 (2019).

Accès Salle des séminaires FAST-LPTMS (Bât. 530, salle C.120, 1ER)