title: Seafloor doming driven by degassing processes unveils sprouting volcanism in coastal areas.
abstract: We report evidences of active seabed doming and gas discharge few kilometers offshore from the Naples harbor (Italy). Pockmarks, mounds, and craters characterize the seabed. These morphologies represent the top of shallow crustal structures including pagodas, faults and folds affecting the present-day seabed. They record upraise, pressurization, and release of He and CO2 from mantle melts and decarbonation reactions of crustal rocks. These gases are likely similar to those that feed the hydrothermal systems of the Ischia, Campi Flegrei and Somma-Vesuvius active volcanoes, suggesting the occurrence of a mantle source variously mixed to crustal fluids beneath the Gulf of Naples. The seafloor swelling and breaching by gas upraising and pressurization processes require overpressures in the order of 2-3 MPa. Seabed doming, faulting, and gas discharge are manifestations of non-volcanic unrests potentially preluding submarine eruptions and/or hydrothermal explosions.
authors.affiliation: Istituto per l'Ambiente Marino Costiero, Consiglio Nazionale delle Ricerche, Naples, Italy.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Passaro
authors.affiliation: Istituto per l'Ambiente Marino Costiero, Consiglio Nazionale delle Ricerche, Naples, Italy.
authors.forename: Stella
authors.initials: S
authors.lastname: Tamburrino
authors.affiliation: Istituto per l'Ambiente Marino Costiero, Consiglio Nazionale delle Ricerche, Naples, Italy.
authors.forename: Mattia
authors.initials: M
authors.lastname: Vallefuoco
authors.affiliation: Dipartimento di Scienze della Terra, Università di Firenze, Florence, Italy.|Istituto di Geoscienze e Georisorse, Consiglio Nazionale delle Ricerche, Florence, Italy.
authors.forename: Franco
authors.initials: F
authors.lastname: Tassi
authors.affiliation: Dipartimento di Scienze della Terra, Università di Firenze, Florence, Italy.|Istituto di Geoscienze e Georisorse, Consiglio Nazionale delle Ricerche, Florence, Italy.
authors.forename: Orlando
authors.initials: O
authors.lastname: Vaselli
authors.affiliation: Dipartimento di Scienze della Terra, Università di Firenze, Florence, Italy.|Istituto di Geoscienze e Georisorse, Consiglio Nazionale delle Ricerche, Florence, Italy.
authors.forename: Luciano
authors.initials: L
authors.lastname: Giannini
authors.affiliation: Istituto Nazionale di Geofisica e Vulcanologia, Bologna, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Chiodini
authors.affiliation: Istituto Nazionale di Geofisica e Vulcanologia - Osservatorio Vesuviano, Naples, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Caliro
authors.affiliation: Istituto per l'Ambiente Marino Costiero, Consiglio Nazionale delle Ricerche, Naples, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Sacchi
authors.affiliation: Istituto Nazionale di Geofisica e Vulcanologia, Palermo, Italy.
authors.forename: Andrea Luca
authors.initials: AL
authors.lastname: Rizzo
authors.affiliation: Istituto per l'Ambiente Marino Costiero, Consiglio Nazionale delle Ricerche, Naples, Italy.|Istituto Nazionale di Geofisica e Vulcanologia, Roma, Italy.
authors.forename: Guido
authors.initials: G
authors.lastname: Ventura