Work

3D structure and dynamics of Campi Flegrei enhance multi-hazard assessment

Year: 2025

Type: article

Abstract: Campi Flegrei is an active caldera in a populated area, currently experiencing significant ground uplift and seismicity. Leveraging seismicity relocations, here we obtain high resolution, 3D P- and S-wave seismic images which we combine with a tailored rock physics experiment to define key features of the caldera’s structure: gas-rich reservoir below 2 km depth, deformed caprock at 1–2 km depth, and basement below 3.5 km depth. Seismicity migrates downwards from the caprock and changes in stress loading trigger deeper, higher events along the inner-caldera boundary faults. The reservoir closely correlates the area of maximum uplift, where deformation acceleration due to pore-fluid pressure is corroborated by laboratory experiments using site-relevant rock. The interaction between the pressurized gas-reservoir and the confining caprock drives the ground uplift. Our results indicate that seismic activity and the potential for a phreatic explosion should be considered as plausible scenarios, prompting a re-evaluation of the hazard assessment. This study maps Campi Flegrei caldera’s internal structure, linking a gas-enriched reservoir and a deformed caprock to ground uplift and earthquakes. Land instability, seismic events and the risk of a phreatic explosion prompt for updated multi-hazard assessments.

Source: Nature Communications

DOI: 10.1038/s41467-025-59821-z