1. ISTerre, CNRS UMR 5275, IFSTTAR, Université Grenoble Alpes, Campus Universitaire, 1381, rue de la Piscine, 38041 Grenoble Cedex 9, France, philippe.roux@univ-grenoble-alpes.fr
2. Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences, Public Law Foundation State of Brandenburg, Telegrafenberg, D‐14473 Potsdam, Germany
3. Department of Mathematics, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
4. Now at Institute of Seismology, University of Helsinki, Helsinki, Finland.
5. Sisprobe Inc., 24 Allée des Vulpains, 38240 Meylan, France
6. Royal Observatory of Belgium, Ringlaan 3, 1180 Brussels, Belgium