1. Laboratoire Magmas et Volcans, Université Blaise Pascal, 5 Rue Kessler, 63038 Clermont Ferrand, France
2. European Commission – Joint Research Centre, Institute for the Protection and the Security of the Citizen, Via Enrico Fermi 2749, TP 680, 21027 Ispra (VA), Italy
3. Geological and Mining Engineering and Sciences, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931, USA
4. Géosciences Montpellier, UMR 5243, Université de Montpellier, Campus Triolet CC060, Place Eugène Bataillon, 34095 Montpellier cedex 05, France