Measurement of Seafloor Deformation in the Marine Sector of the Campi Flegrei Caldera (Italy)

Abstract

We present an assessment of vertical seafloor deformation in the shallow marine sector of the Campi Flegrei caldera (southern Italy) obtained from GPS and bottom pressure recorder (BPR) data, acquired over the period April 2016 to July 2017 in the Gulf of Pozzuoli by a new marine infrastructure, MEDUSA. This infrastructure consists of four fixed buoys with GPS receivers; each buoy is connected by cable to a seafloor multisensor module hosting a BPR. The measured maximum vertical uplift of the seafloor is about 4.2 ± 0.4 cm. The MEDUSA data were then compared to the expected vertical displacement in the marine sector according to a Mogi model point source computed using only GPS land measurements. The results show that a single point source model of deformation is able to explain both the GPS land and seafloor data. Moreover, we demonstrate that a network of permanent GPS buoys represents a powerful tool to measure the seafloor vertical deformation field in shallow water. The performance of this system is comparable to on‐land high‐precision GPS networks, marking a significant achievement and advance in seafloor geodesy and extending volcano monitoring capabilities to shallow offshore areas (up to 100 m depth). The GPS measurements of MEDUSA have also been used to confirm that the BPR data provide an independent measure of the seafloor vertical uplift in shallow water.

Radial interpolation of GPS and leveling data of ground deformation in a resurgent caldera: application to Campi Flegrei (Italy)

“…In summary, the ground displacement measurements recorded at Campi Flegrei in the last 39 years generally show approximately radial patterns both in terms of intensity and orientation, i.e., axial symmetry (Corrado et al 1977;Berrino et al 1984;Bianchi et al 1987;Orsi et al 1999;De Martino et al 2014a, b;Amoruso et al 2014a, b;Iannaccone et al 2018). The maximum vertical displacement (uplift or subsidence) is located in the town of Pozzuoli, in the central part of the Campi Flegrei caldera (benchmark 25, Fig.…”

“…A total of 25 stations are present (20 inland and 4 in the Pozzuoli Gulf) covering an area of about 130 km 2 . More details on data recording and processing are described in De Martino et al (2014a, b) and Iannaccone et al (2018). Inland GPS devices provide measurements of the ground displacement as 3D vectors composed of vertical (1D) and horizontal (2D) components, while the offshore stations measure the vertical displacements only (De .…”

“…13b). The estimation ΔV3 does not rely on the interpolation of the vertical deformation occurred underwater, far from any GPS/leveling station before the recent placement of the GPS buoys (De Iannaccone et al 2018). Finally, a fourth estimation (named ΔV4) considers the portion of this circular sector that is less than 6 km from the center.…”

Surface Temperature Multiscale Monitoring by Thermal Infrared Satellite and Ground Images at Campi Flegrei Volcanic Area (Italy)

“…CFc is affected by ground vertical movements (Bradyseism) and in modern times, two significant episodes of ground uplift have occurred, with a maximum uplift of about 3.5 m in the area of Pozzuoli [44]. In the last ten years the same area has been affected by ground uplift, with vertical displacement of about 400 mm in the period 2008-2018 [45]. At present, the Solfatara area ( Figure 1) is the highly hydrothermally active zone of Campi Flegrei, with diffuse fumaroles inside and beside the crater.…”

Insight Into Campi Flegrei Caldera Unrest Through Seismic Tremor Measurements at Pisciarelli Fumarolic Field

“…Starting from 2004, changes in seismicity (Chiodini et al, ; D'Auria et al, ; Saccorotti et al, ), deformation (Troise et al, ; Trasatti et al, ; D'Auria et al, ; De Martino et al, ; Giudicepietro et al, ; Iannaccone et al, ), and degassing activity (Cardellini et al, ; Chiodini et al, ; Chiodini et al, ; Tamburello et al, ) became evident in the Campi Flegrei caldera. These changes were the subject of scientific investigations that resulted in a remarkable production of articles over the recent years (Amoruso et al, ; De Siena et al, ; Di Luccio et al, ; Giudicepietro et al, ; Kilburn et al, ; Zaccarelli & Bianco, ; Zollo et al, ).…”