P-wave velocity and density structure beneath Mt. Vesuvius: a magma body in the upper edifice?

摘要: A high-resolution image of the compressional wave velocity and density structure in shallow edifice Mount Vesuvius has been derived from simultaneous inversion travel times hypocentral parameters local earthquakes gravity inversion. The robustness tomography solution improved by adding to earthquake data a set land based shots, used for constraining time residuals. results give high resolution P-wave with details down 300-500 m. relocated seismicity appears extend 5 km depth below central crater, distributed into two clusters, separated an anomalously Vp region positioned at around 1 depth. zone Vp/Vs ratio upper layers is interpreted as produced presence intense fluid circulation alternatively interpretation terms small magma chamber inferred petrologic studies. In this shallower minimum energy, whilst most high-energy quakes (up Magnitude 3.6) occur cluster located greater be along almost vertical cracks, delimited body past intrusive body, corresponding remnants Mt. Somma. framework performed study part volcano. Gravity have inverted using method suitable application scattered relevant topography on discretization investigated medium establishing approximation triangular mesh. results, retrieved distribution, pattern exclude significant reservoirs close conduit. These should higher than that base hypocenter volume, evidenced previous