Étudiant : GOUNON Alisson
Directeur de thèse : LATOUR Soumaya (IRAP) et LETORT Jean (IRAP)
Début de thèse : Octobre 2019
Groupe thématique : DIP
Earthquakes are produced by sudden slip instabilities that occurs in seismic faults, that rapidly relax seismic stresses accumulated slowly during the long preceding inter-seismic phase. Rupture dynamics studies focus on understanding how does the slip begins, propagates, and stops along the fault. This process is still poorly understood due to the fact it is a physical instability, and is thus a non-linear and multi-scale problem. These characteristics make it challenging to observe and also to model ruptures, both analytically and numerically. In this project, we propose to use an existing friction experiment to better understand several aspects of seismic rupture dynamics and to compare it with the analysis of seismic and geodetic data for large earthquakes. We will first characterize the effects of fault heterogeneity on the initiation phase of the rupture. This should bring a new light on recent seismic and geodetic observations that seem to indicate that such a slow ‘pre-seismic’ phase does exist for natural earthquakes. Secondly, we will investigate the generation of high frequency sesismic waves dues to complexities of the rupture propagation. Finally, we will work on quantifying the effect of stress heterogeneity on the fault. This will allow to test the validity of analytical and numerical models that are usually used to describe seismic rupture.