Beam propagation in the ocean: Quasi-particle approach

In this paper the Quasi-Particle (QP) technique has been applied for the first time to the study of beam propagation in slowly varying sound-speed profiles with an upper boundary, typical of some underwater acoustic environments. With the aim of testing the possibilities and the limitations of this new technique, particular attention has been devoted to special effects. The results of this analysis have been used to give some criteria for a proper modeling of the ocean environment from the Quasi-Particle point of view.     

Long-time variation of soil CO2 fluxes at the summit crater of Vulcano (Italy)

Here, we report the first continuous data of geochemical parameters acquired directly from the active summit crater of Vulcano. This approach provides a means to better investigate deep geochemical processes associated with the degassing system of Vulcano Island. In particular, we report on soil CO₂ fluxes from the upper part of Vulcano, a closed-conduit volcano, from September 2007 to October 2010. Large variations in the soil CO₂ and plume SO₂ fluxes (order of magnitude), coinciding with other discontinuous geochemical parameters (CO₂ concentrations in fumarole gas) and physical parameters (increase of shallow seismic activity and fumarole temperatures) have been recorded. The results from this work suggest new prospects for strengthening geochemical monitoring of volcanic activity and for improving the constraints in the construction of a “geochemical model”, this being a necessary condition to better understand the functioning of volcanic systems.