[1] CNR, Natl Res Council, Inst Geosci & Earth Resources, I-00185 Rome, Italy
[2] Politecn Torino, Dept Environm Land & Infrastruct Engn, I-10129 Turin, Italy
[3] Univ Padua, Dept Geosci, I-35100 Padua, Italy
[4] Aarhus Geophys, Aarhus, Denmark
[5] Univ Erlangen Nurnberg, GeoZentrum Nordbayern, Erlangen, Germany
[6] Univ Padua, Dept Land Environm Agr & Forestry, I-35100 Padua, Italy
[7] Univ Florence, Dept Earth Sci, I-50121 Florence, Italy