Stanford researchers have identified groundwater pressure, not magma movement, as the primary driver of seismic unrest in Italy’s Campi Flegrei caldera, suggesting new avenues for mitigating earthquake risks.
Key Points at a Glance
- Earthquakes in Campi Flegrei are linked to pressure buildup in a geothermal reservoir beneath Pozzuoli.
- Managing groundwater levels could reduce seismic activity in the region.
- The caldera’s caprock has self-sealing properties, creating a closed system that traps pressure.
- Historical data and lab experiments support the new model of pressure-induced seismicity.
Recent research from Stanford University has unveiled that the seismic unrest in Italy’s Campi Flegrei caldera is primarily driven by pressure buildup in a geothermal reservoir, rather than the previously assumed magma movement. This discovery opens up potential strategies for mitigating earthquake risks in the densely populated region west of Naples.
The Campi Flegrei caldera has experienced increased seismic activity since 2022, with patterns resembling those observed during the 1982–1984 unrest. Stanford scientists, through subsurface imaging and laboratory experiments, have demonstrated that the accumulation of water and vapor in the geothermal reservoir leads to pressure buildup. When the caprock, acting as a lid, seals the reservoir, the trapped pressure can cause ground deformation and earthquakes.
The study, published in Science Advances on May 2, 2025, challenges the long-held belief that magma movement is the primary cause of seismic activity in the area. Instead, it highlights the role of groundwater recharge in influencing seismic events. Data from a well in Naples show that water levels have been steadily rising over the past 24 years, correlating with periods of increased seismicity.
Laboratory experiments conducted by the research team replicated the conditions of the geothermal reservoir. Using a setup analogous to a moka pot, they demonstrated how mineral fibers form within the caprock, sealing cracks and creating a closed system. This sealing process allows pressure to accumulate until it is released through fracturing, leading to earthquakes.
The researchers propose that managing surface runoff and groundwater levels could mitigate the pressure buildup, thereby reducing seismic activity. Restoring and maintaining water channels, some of which date back to the 16th century, could be a practical approach to controlling the water flow into the geothermal reservoir.
This new understanding of Campi Flegrei’s seismic behavior emphasizes the importance of proactive measures in volcanic regions. By focusing on groundwater management, authorities could potentially prevent or lessen the impact of future seismic events, safeguarding the communities residing in and around the caldera.
Source: Stanford University
