Oceanic transform faults are among the less well-known features of the ocean floor. In the recent years, much has been done to understand their thermo-mechanical structure and the deformation associated with local and far field stresses. Among these features, complex multi-fault systems, where very short spreading segments are offset by large transform faults, are most interesting, especially those at slow spreading ridges, where transform faults are supposed to be cold geological settings. Studying such systems can bring new information on the relative roles of the mantle and the lithosphere on the spreading processes and on the origin and evolution of large offset transform faults. Here, I will present work done on the multi-fault system of St. Paul in the slow spreading Equatorial Mid-Atlantic ridge. The evolution of such intra-transform spreading systems raises the question of how cold transform faults are and of their effect on the spreading processes

1. Deformation along oceanic transform faults is controlled by kinematic changes and by local processes, including the nature of the underlying mantle.
2. Oceanic transform faults may not be as cold as previously supposed.
3. Intra-transform spreading processes are mainly controlled by the nature of the mantle.

After a PhD at Université Paris-Sud, Orsay, I joined the Marine Geosciences group at Université de Brest as a CNRS researcher. My research topics are mainly on mid-oceanic ridge processes, their interactions with mantle plumes and, more recently, oceanic transform faults and fracture zones. I also do research on deep sea instrumentation and am working on a gravity sensor for AUVs.