PIEZOMAGNETIC EFFECTS INDUCED BY ARTIFICIAL SOURCES ON MT. VESUVIO (ITALY)

C. Del Negro & R. Napoli (Istituto Internazionale di Vulcanologia, CNR, Piazza Roma 2, 95123 Catania, Italy)

Traditionally, ground deformations and seismic activity studies are used to detect the precursory signals of volcanic eruptions. Both methods point out local phenomena such as a rupture along a fault plane or local deformations along a fissure system. Therefore, these techniques can be usefully supported for monitoring volcanic activity by the magnetic method which integrates the effect of a phenomenon over a large volume. However, verification of the possibility of measuring changes in the magnetic field associated with volcanic activity has been going on for a long time. In order to prove the existence of vulcanomagnetic effects associated with mechanical stress, measurements in continuous of the magnetic field were executed during the three-dimensional seismic tomography carried out at Mt. Vesuvio. In some cases, remarkable changes in the intensity of the magnetic field in correspondence to explosions were observed.