New magnetic surveys of an active undersea volcanic system located off the west coast of Italy, at the Campi Flegrei and the island of Ischia, have identified a number of hitherto unknown geological structures on the seafloor, including the remnants of an ancient caldera and a vast landslide. This is according to a study conducted by a team of researchers from the National Institute of Geophysics and Volcanology (INGV) and the Institute of Marine Sciences of the National Research Council (CNR-ISMAR), recently published in the scientific journal “Geomorphology”. The Phlegraean Fields, well known for their historical volcanic activity and more recent bradyseismic phenomena, have been the subject of numerous studies, but until now their underwater portion had not been analyzed and represented in an integrated way with the marine sectors in front of them. New magnetic surveys, conducted in 2022 by air and ship surveys, have detected significant magnetic anomalies indicating the presence of an ancient submerged volcano just west of Ischia.