Reappraisal of Holocene Caldera Resurgence at Campi Flegrei (Southern Italy): A Long‐Lived Magma‐Driven Resurgent Dome System

Abstract

Caldera systems commonly experience inner resurgence, which shapes patterns of volcanic activity. However, incomplete reconstructions of past ground deformation can lead to incorrect recognition of precursory signals. The Campi Flegrei caldera (Italy) provides an exceptional opportunity to address this issue as uplifted marine sediments interlayered with pyroclastic deposits preserved repeated Holocene deformation. Here, we reassess the mechanisms and evolution of caldera resurgence at Campi Flegrei by integrating previous data sets with new observations from the submerged sector, providing improved spatial and temporal constraints. We document ∼190 m of permanent uplift over the last 10.5 kyr, expressed as a ∼9‐km‐wide, bell‐shaped pattern centered on the city of Pozzuoli. This pattern is best explained by the incremental growth of a resurgent dome controlled by magma emplacement at ∼3–4 km depth in a stacked‐sill configuration. Our reconstruction shows that, since resurgence began at 10.5 ka, the volume of shallow intruded magma has been approximately three times greater than the erupted volume, implying dampened eruptive activity. Nevertheless, temporal overlaps between uplift phases and eruptions indicate a direct link between magma transfer and unrest. Resurgence has also marked the inward migration of eruptive vents and the eruption of more silicic magmas, reflecting a major reorganization of the magmatic system. Localized deformation anomalies that deviate from the main displacement pattern are related to localized intrusions and fault reactivation. These findings identify Campi Flegrei as a resurgent dome system tightly connected to the dynamics of present‐day unrest, which may represent the early stage of a renewed eruptive period.