Geophysical survey to estimate the 3D sliding surface and the 4D evolution of the water pressure on part of a deep seated landslide

Geophysical surveys were conducted on the very unstable front part of the La Clapière landslide in the French Alps (Alpes Maritimes). The electrical resistivity survey was carried out to obtain, for the first time on this deep-seated landslide, 3D information on the slipping surface and the vertical drained faults. Moreover, we planned to follow within time (6 months) the evolution of the saturated zones (presence of gravitational water) and their percolation into the shearing zones. Our 4D results showed the importance of the complex water channelization within the slope and relation to geological discontinuities.