Near-surface Voids in the Neapolitan Volcanic Tuff (Italy) Detected by Seismic Refraction Tomography

摘要

The Neapolitan area (Italy) is affected by the presence of shallow man-made cavities in volcanic tuffs that were used in the past as building material. Therefore, the identification of these voids is a fundamental prerequisite for the minimization of subsurface collapse risks. In the past few years, several authors have shown that the geophysics prospecting methods can provide a most convenient solution to detecting underground voids. In this work we show how the seismic refraction tomography represents a powerful tool for the detection of near-surface tuff-cavities located in Casamarciano, Naples. The interpolation of the velocity models, allowed us to build a three-dimensional model of the tuff basement top and to show the lateral extend of the voids. The cavity location detected by seismic refraction tomography has been subsequently confirmed by four core-drilling made in the area.