Аннотация:A seismic array of 11 stations maintained for 9 years—from 1985 to 1994—provided data that were exploited for the investigation of the 3-D structure of the upper crust in the Gioia Tauro basin, south-western Calabria, Italy. A data set of 207 local earthquakes that were located with a minimum of seven observations, a traveltime residual of ≤0.3 s rms and an azimuthal gap ≤180° was used to compute first a minimum 1-D velocity model for the Gioia Tauro region, which served as initial model for the subsequent 3-D inversion. The inversion for 3-D P-velocity crustal structure was performed by iteratively solving the coupled hypocentre-velocity problem in a least-squares sense. Careful analysis of the resolution capability of our data set outlines the well-resolved features for interpretation. The resulting 3-D velocity model of the Gioia Tauro region shows, in the upper crust, generally higher average velocities in the south and lower average velocities in the north. A pronounced northeast-southwest trending zone of low velocities in the upper 12 km was identified in the area of the Cittanova fault zone (CFZ). Because of the limited dimensions of the seismic array the half graben of Gioia Tauro basin could not be recognized in the tomographic images.
