Njord Seminar with Osvanny Ramos

Njord Seminar with Osvanny Ramos (Université Claude Bernard Lyon 1): The LabQuakes project - from a granular fault to earthquake statistics

A poster for a Njord seminar showing presenter, title, date, Njord seal, and Zoom link.


Building analogue experiments that are able to simplify the huge complexity of earthquakes, while capturing the essential ingredients of their dynamics, is a plausible approach to better understand them. In this quest many different experimental systems have obtained statistical relations similar to those that describe seismicity: Gutenberg-Richer (G-R) law, Omori law, interevent time distribution, etc. However, many of these similarities are qualitative; for example: the distribution of events’ energy follows a power law with an exponent value different to the one of the G-R law. Recently we have developed an experimental system, based on the continuous and slow shear of a compressed granular system that mimics the behaviour of a tectonic fault: elastic energy is slowly stored in the granular structure and liberated by sudden reorganization events accompanied by acoustic emissions. By capturing and analysing a few millions of these laboratory quakes, we are able to reproduce quantitatively and simultaneously the main statistical relations describing seismicity [1]. This a strong indication that both systems share a common physics and brings hopes to a better understanding of earthquake physics.
This talk will briefly discuss, with some examples, the relevance of reaching a quantitative agreement in earthquake analogue experiments, then the main results obtained in our experimental system [1], and the challenges we are currently focusing on [2,3].
[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).
[2] V. Levy dit Vehel,T. Hatano, L. Vanel, K. J. Måløy and O. Ramos, Dilation as a precursor in a continuous granular fault,  EPJ Web of Conferences 249, 15006 (2021).

[3] V. Levy dit Vehel, A. Haddjeri, and O. Ramos, Acoustic localisation in a two-dimensional granular medium, EPJ Web of Conferences 249, 15005 (2021).

You will find the complete schedule for Njord Seminar Series spring '22 here.

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Published Jan. 10, 2022 2:11 PM - Last modified Jan. 10, 2022 2:25 PM