Seismicity cycles in the Mt. Vesuvius area and their relation to solar flux and the variations of the Earth's magnetic field
A local seismic network has been continuously monitoring the earthquake activity around the volcano Mt. Vesuvius for about 25 years. A total number of 7800 events have been recorded. The earthquakes have not exceeded a magnitude of 3.4. This considerable volume of data makes it possible to carry out several analyses regarding temporal changes of seismic activity in the volcano region, which are of interest for geodynamic and risk considerations. From the analyses, results of general nature can also be obtained: The present study indicates that the variations of solar activity and of the Earth's magnetic field are in close relation to earthquake activity. The latter relationship between geomagnetic field and seismicity has already been suggested by an earlier study (Duma, 1996). However, mainly observational results will be presented in this paper, rather than explanations of these phenomena.