I am a specialist of seismogenic faults. My research focuses on fault and earthquake mechanics, primarily approached through empirical observation of natural features. I search to identify and document the possible generic properties of faults and of large earthquakes, and I examine how fault properties control large earthquake properties such as slip amplitude, rupture extent, ground accelerations, etc. In recent years, I have also developed novel approaches in paleoseismology dedicated to recover long, large earthquake records. My work is driven by an attempt to provide key observations that may feed our understanding of fault and earthquake physics, and help us to better assess seismic hazard.