Separation of intrinsic and scattering Q for volcanic areas: A comparison between Etna and Campi Flegrei

We studied the seismic attenuation in the short period,range (1-24 Hz) at the Campi Flegrei volcanic area, using the method of Frankel (1991) to separate intrinsic and scattering attenuation parameters. The results, compared to those obtained at Etna volcano, show that scattering phenomena play a main role in the attenuation mechanism of the seismic waves for these two volcanic areas. The comparison of the present results with those obtained in non volcanic areas, allow us to re-consider the importance of the molten materials (magma) as a main cause of the seismic attenuation in the active volcanic areas.