The Neapolitan volcanic area includes three active and high-risk volcanoes: Campi Flegrei caldera, Somma–Vesuvius, and Ischia island. The Campi Flegrei volcanic area is a typical example of a resurgent caldera, characterized by intense uplift periods followed by subsidence phases (bradyseism). After about 21 years of subsidence following the 1982–1984 unrest, a new inflation period started in 2005 and, with increasing rates over time, is ongoing. The overall uplift from 2005 to December 2019 is about 65 cm. This paper provides the history of the recent Campi Flegrei caldera unrest and an overview of the ground deformation patterns of the Somma–Vesuvius and Ischia volcanoes from continuous GPS observations. In the 2000–2019 time span, the GPS time series allowed the continuous and accurate tracking of ground and seafloor deformation of the whole volcanic area. With the aim of improving the research on volcano dynamics and hazard assessment, the full dataset of the GPS time series from the Neapolitan volcanic area from January 2000 to December 2019 is presented and made available to the scientific community.

After a period of mild eruptive activity, Stromboli showed between 2017 and 2018 a reawakening phase, with an increase in the eruptive activity starting in May 2017. The alert level of the volcano was raised from “green” (base) to “yellow” (attention) on 7 December 2017, and a small lava overflowed the crater rim on 15 December 2017. Between July 2017 and August 2018 the monitoring networks recorded nine major explosions, which are a serious hazard for Stromboli because they affect the summit area, crowded by tourists. We studied the 2017–2018 eruptive phase through the analysis of multidisciplinary data comprising thermal video-camera images, seismic, geodetic and geochemical data. We focused on the major explosion mechanism analyzing the well-recorded 1 December 2017 major explosion as a case study. We found that the 2017–2018 eruptive phase is consistent with a greater gas-rich magma supply in the shallow system. Furthermore, through the analysis of the case study major explosion, we identified precursory phases in the strainmeter and seismic data occurring 77 and 38 s before the explosive jet reached the eruptive vent, respectively. On the basis of these short-term precursors, we propose an automatic timely alarm system for major explosions at Stromboli volcano.

Ischia is a volcanic island, west of the caldera of Campi Flegrei, southern Italy. Since the deployment of a modern seismic network in 1970, until the 21 August 2017 earthquake, the seismicity of Ischia has been characterized by low‐magnitude ($Md≤2.3$) earthquakes located in the northern part of the island, mostly beneath the town of Casamicciola Terme at very shallow depths ($∼500m$). Some of these events seem to have occurred on the same seismogenetic structure in the northern part of the island. This area coincides with that where the devastating events of 1881 and 1883 occurred and where the small‐magnitude seismicity recorded between 1927 and 1936 was located. The August 2017 seismic sequence affected the same area. The current network configuration is able to locate shallow events with $Md≥1.0$ and to detect smaller earthquakes or other types of natural and artificial events (e.g., blast fishing, geothermal well explosions; see The Seismic Network section). Here, we present the catalog of earthquakes recorded on Ischia between 1999 and February 2018 and compare the August 2017 seismic sequence with the background seismicity. Furthermore, we identified a sequence of events possibly linked to the explosion of a geothermal well on the island.