1. CEA−DAM−Île‐de‐France, Bruyères‐le‐châtel, F‐91297 Arpajon, France, Olivier.sebe@cea.fr
2. Deceased (2016).
3. Université Grenoble Alpes–CNRS–IFSTTAR‐IRD, ISTerre, CS 40700, F‐38058 Grenoble, Cedex 9, France, Pierre-yves.bard@univ-grenoble-alpes.fr