Fluid migration in sedimentary layers is at the origin of puzzling fluid-escape structures in the oldest part of the oceanic floor, close to continental margins. Although apparently innocuous, these structures are among the most threatening geohazards, from offshore drilling incidents to the largest massive extinctions on Earth. To understand their origin and evolution, based on laboratory experiments, we investigate the dynamics of immersed granular layers submitted to a localized fluid injection. In a given range of parameters and for different experimental configurations, the system exhibits periodic fluidization patterns, either in time or in space. The importance of such phenomena will be discussed in regards to geophysical and environmental applications.
Accès Salle des séminaires FAST-LPTMS (Bât. 530, salle C.120, 1er)