1. Istituto Nazionale di Geofisica e Vulcanologia (INGV), Via di Vigna Murata, 605, 00143 Rome, Italy. E-mail: mollo@ingv.it
2. Laboratoire de Déformation des Roches, Équipe de Géophysique Expérimentale, Institut de Physique de Globe de Strasbourg, UMR 7516 CNRS, EOST, Université de Strasbourg, Strasbourg, France
3. Earth and Environment, LMU – University of Munich, Theresienstr. 41/III, 80333 Munich, Germany
4. Dipartimento INGEO, Università G. d'Annunzio, Chieti, Italy
5. Bayerisches Geoinstitut, Universität Bayreuth, Bayreuth, Germany
6. Department of Geology, University of Leicester, University Road, Leicester, LE1 7RH, UK
7. British Geological Survey, Environmental Science Centre, Keyworth, Nottingham, NG12 5GG, UK