  Accurate description of the topography of active faults surfaces represents
an important geophysical issue because this topography is strongly related to
the stress distribution along fault planes, and therefore to processes
implicated in earthquake nucleation, propagation, and arrest. With the recent
development of Light Detection And Ranging (LIDAR) apparatus, it is now
possible to measure accurately the 3D topography of rough surfaces with a
comparable resolution in all directions, both at field and laboratory scales.
In the present study, we have investigated the scaling properties including
possible anisotropy properties of several outcrops of two natural fault
surfaces (Vuache strike-slip fault, France, and Magnola normal fault, Italy) in
limestones.
