1. Faculty of Geology and Geoenvironment, National and Kapodistrian University of Athens, 15774 Athens, Greece
2. Department of Geological Sciences, School of Mining & Metallurgical Engineering, National Technical University of Athens, 15773 Athens, Greece
3. Dipartimento di Fisica e Astronomia (DIFA), Settore Geofisica, Alma Mater Studiorum Università di Bologna, 40126 Bologna, BO, Italy