Full three-dimensional relocation and tomographic inversion of the 1977-2008 earthquakes in north-eastern Italy: A feasibility study

In a regional seismological network, the estimation of the epicenter is usually robust, especially for events inside or close to the network boundaries. In contrast, the hypocentral depth is very sensitive to the assumed velocity field. In this study, we compare the hypocenter estimates obtained by a classical algorithm in a simple one-dimensional (1D) model with a recently developed full 3D model that is based on shrinking grids. This study is preliminary, as the 3D Earth model is based on limited data from the literature; however, it demonstrates that different patterns show up when a more representative geological model is adopted. This encourages further studies, based on fully integrated 3D models from active surface seismic, well data and other geophysical measurements. Such an integrated approach has been successfully adopted by the oil and gas industries for decades, which has increased the exploration success rate and the production of hydrocarbon reservoirs.