3D tomographic imaging of the southern Apennines (Italy): A statistical approach to estimate the model uncertainty and resolution

A new dataset of first P-wave arrival times is used to derive the 3D tomographic
model of the Campania-Lucania region in the southern Apennines (Italy). We address the
issue related to the non-uniqueness of the tomographic inversion solution through massive
numerical experimentation based on the global exploration of the model parameter space
starting from a large variety of physically plausible initial models. The average of all the
realizations is adopted as the best-fit solution and the uncertainty of the model parameters
is studied using a statistical approach based on a Monte Carlo-type analysis. How the
uncertainty in the initial model, earthquake locations, and data influences the inversion
result is studied by considering separately the individual effects. Checkerboard tests are
performed to estimate the resolving power of the dataset. Re-located seismicity in
a reliable new 3D tomographic model allows us to correlate the earthquake distribution
with the main seismogenic structures present in the area.

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