High-Resolution DEM Extraction from Terrestrial LIDAR Topometry and Surface Kinematics of the Creeping Alpine Permafrost : The Laurichard Rock Glacier Case Study (Southern French Alps)

International audienceThe most common landforms associated with the creep of Alpine permafrost are the rock glaciers, the morphology of which reflects the complex processes of the internal deformation of the ice and debris mixture. In the present study, a terrestrial LIDAR device was employed to scan, at a sub-decimeter resolution, the surface of the Laurichard active rock glacier (Southern French Alps). Two points-clouds were generated at one-year interval (Sept. 2005 and Sept. 2006) and processed in order to produce two high-resolution digital elevation models (DEMs) and to compare them. Different methods were used in order to extract small-scale topography, quantify interannual surface changes, and determine the kinematic behavior of the creeping mass. For a better understanding of rock glacier dynamics, the results have also been compared to the geodetic measurements annually over a 20-year period, and to the geophysical evidences of rock glacier internal structure