The recurrence of geophysical manifestations at the Campi Flegrei caldera.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 40315308.
- Also identified by DOI 10.1126/sciadv.adt2067 and PMC identifier 12047431.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The Campi Flegrei caldera (CFc), Italy, exhibits distinct unrest patterns, including shallow seismicity following substantial strain accumulation, all within a densely populated area. Previous geophysical studies typically analyzed individual episodes, but by comparing two distinct unrest periods we identified recurring manifestations and <i>V</i><sub>P</sub>/<i>V</i><sub>S</sub> anomalies linked to a confined reservoir at 2- to 4-kilometer depth. Integrating rock physics experiments under hydrothermal conditions, 24 years of rainfall data, and subsurface hydrodynamics, we found increasing rainfall rates, which indicate reservoir recharge and pressurization. We show that hydrothermal water promotes caprock sealing through the formation of a fibrous microstructure. Our experiments further demonstrate that fluid accumulation rates directly influence deformation rates. Together, these processes drive gradual deformation, natural seismicity, and deepening earthquake foci. Recognizing these recurring patterns is crucial for understanding the caldera's unrest-driving mechanism, enabling us to offer actionable insights for hazard assessment and engineering solutions, such as intercepting water upstream to prevent drainage toward Pozzuoli.