Results from reprocessing the vintage 1978 ENI-ENEL seismic reflection profiles acquired on the onshore of Campi Flegrei

In 1978, seven seismic reflection profiles were acquired through a joint venture between Agip and Enel to explore geothermal resources in the Campi Flegrei caldera. These vintage profiles reflect the technological limitations of that era: sparse shot points, limited channels, low bandwidth and dynamic range, resulting in a low signal-to-noise ratio, especially near volcanic structures. Despite these limitations, they can offer invaluable insights in Campi Flegrei, where obtaining new seismic data is impractical due to urbanization, environmental concerns, and intensified volcanic hazards.

This presentation shares the outcomes of a reprocessing aimed at enhancing profile signal-to-noise ratio. Given acquisition geometry and data quality, contemporary seismic processing methods like pre-stack depth imaging, reflection tomography, and full-waveform inversion are impractical. The reprocessing adapted to data quality limitations, utilizing time-domain algorithms. It involved assigning a crooked line geometry, conventional common-midpoint (CMP) processing, and less conventional common reflection surface (CRS) processing. CRS stacking, not reliant on stacking velocity estimation, improves seismic imaging quality. P-wave velocity models were reconstructed along the profiles through tomography algorithms applied to picked first arrivals. Post-stack time migration and depth conversions with vertical stretching were applied to CDP/CRS stacks.

Despite limitations, these depth images, tied to exploration wells and geophysical logs, can significantly contribute to understanding the near-surface structure of this dynamic region and its structural and stratigraphic relations with the sedimentary Volturno Plain to the North.