1. Department of Geophysics, Spanish Navy Observatory, San Fernando, Spain
2. Department of Geology, Universidad de Oviedo, Oviedo, Spain
3. Institute of Geoscience, University of Potsdam, Potsdam-Golm, Germany
4. Institute of Marine Sciences, Barcelona, Spain
5. Institute of Rock Structure and Mechanics, Czech Academy of Sciences, Prague, Czechia
6. Department of Earth and Planetary Sciences, Northwestern University, Evanston, Illinois, U.S.A.
7. Seismology Department, Instituto Geográfico Nacional, Madrid, Spain
8. Department of Signal Theory, Telematics and Communications, University of Granada, Granada, Spain