Magnetic variation analysis for the June 1993 seismic events in Central Italy

A scientific collaboration between the Istituto Nazionale di Geofisica (Italy) and the Warsaw Academy of Science (Poland) gave rise to the installation of a few stations for the long-term measurement of magnetotelluric fields in Central Italy. The investigation sites were determined following the individual seismic interest of each location. For this project, the magnetic observatory in L'Aquila was also equipped with electric lines, for simultaneous measurements of the telluric field. After a few years of experience some of the installed stations had to be removed for their high noise level that made this study almost impossible. A first time interval was considered from January 1992 to February 1993 and showed the existence of significant changes in magnetotelluric parameters related to earthquake occurrence time, an extension of that analysis was made to include the event of June 1993 using the magnetic field time variation