Physics Dpt, University of Oslo, P.O. Boks 1048 Blindern, N-0316 Oslo 3, Norway, Oslo, 0316, Norway ; Physics of Geological Processes, University of Oslo, P.O. Boks 1048 Blindern, N-0316 Oslo 3, Norway, Oslo, 0316, Norway
Departament d'Estructura i Constituents de la Materia, Facultat de Fisica, Universitat de Barcelona,, Av. Diagonal 647, E--08028 Barcelona, Catalonia, Spain, Barcelona, 0828, Spain ;
Physics Dpt, University of Oslo, P.O. Boks 1048 Blindern, N-0316 Oslo 3, Norway, Oslo, 0316, Norway ;
Departament d'Estructura i Constituents de la Materia, Facultat de Fisica, Universitat de Barcelona,, Av. Diagonal 647, E--08028 Barcelona, Catalonia, Spain, Barcelona, 0828, Spain ;