Alexandre Schubnel (Laboratoire de Géologie, ENS) — January 12, 2017
Because earthquakes are spectacular examples of uncontrollable catastrophes, the opportunity to study them under controlled conditions is unique and is, in fact, the only way to understand in details the physics of earthquake sources.
Following the pioneering work of Brace and Byerlee (1966), we propose a simple idea : to reproduce earthquakes in the laboratory. The advantage of this approach is that, to first order, if the experiment matches real in-situ conditions, the physical processes involved during the dynamic fracture propagation are expected to be the same as those of `real’ earthquakes. In other words, we experimentally constrain the thermodynamic conditions driving dynamic shear crack propagation in rocks, while recording all the parameters that are essential to fully quantify the energy budget during an earthquake.
Our studies demonstrate that dynamic rupture propagation is self-similar and, thus, laboratory earthquakes are not mere earthquake analogs, but real —yet tiny— earthquakes. In particular, our work highlights the significant role played by (mineral) phase transitions in the earthquake energy budget, both during earthquake triggering and during dynamic rupture propagation.
After a PhD obtained in 2002 from the Institut de Physique du Globe de Paris, and a postdoctoral stay at the University of Toronto, Alexandre Schubnel was recruited as a CNRS Researcher at the Laboratoire de Géologie of ENS Paris in 2006. His research interests focus on rock physics and rock mechanics. His major contribution is the development of laboratory seismology, for which he was awarded both the bronze medal of CNRS and the Gouilloud-Schlumberger prize of the French National Academy of Sciences in 2014.