## 4 Results and Discussion
### Hydrothermal Vents and Products of the SE Tyrrhenian Sea  
The SE Tyrrhenian Sea has several seamounts characterized by wide and diffuse vents [72; 73; 74; 75; 76; 77; 78; 79; 80] that give rise to peculiar, site-specific bio-associations [81; 82; 83; 84; 85; 86; 87; 88; 89; 90; 91; 92]. These sites of active (or that were active in the recent past) hydrothermal vents are located on its SE sector, i.e., in the Aeolian Arc, and on the Marsili and Palinuro volcanic chains. The Aeolian Islands archipelago, located in the Southern Tyrrhenian Sea off the northeastern coast of Sicily, consists of seven main islands (Lipari, Vulcano, Salina, Stromboli, Filicudi, Alicudi, and Panarea) and numerous seamounts of volcanic origin. The formation of the archipelago occurred around one million years ago, following the subduction process induced by the movement of the Ionian Sea lithosphere beneath the Calabrian arc. The volcanic activity, which is still ongoing on some of the islands and in the surrounding seabeds, has also produced hydrothermal vents, particularly in Vulcano and Panarea. The geochemical characterization of the gases emitted revealed a dominant presence of CO\({}_{2}\), naturally leading to a decrease in pH levels. Vulcano Island is characterized by the presence of numerous sulfurous fumaroles that can reach 400-550 \({}^{\circ}\)C and hosts one of the most active and studied submarine CO\({}_{2}\) emissions [93; 94; 95; 96]. The composition of the gases emitted consists mainly of CO\({}_{2}\) (around 97-99% vol. ), while small concentrations of toxic gases, such as H\({}_{2}\)S (not exceeding 2.2%), appear to be limited to the primary vent and decrease sharply over short distances (20 m). Additionally, as an indirect effect of the acidification of the area, trace elements, such as Ba, Fe, As, and Cd, have been found in sediments even at significant distances from the primary source. Panarea Island represents the emerged part of an underwater volcano more than 2 km high and approximately 20 km wide, eroded over time by marine erosion and tectonic processes, as well as the presence of hydrothermal events [97; 98; 99; 100; 101]. Off the eastern coast, there is a field of submarine hydrothermal emissions at depths of around 10-15 m. Fluid emissions reach the water column through fractures, and numerous areas have been identified where warm waters and gases permeate through the sand of the seafloor. The emissions (predominantly volcanic CO\({}_{2}\)) have a flow of approximately 106-107 L per day, with temperatures between 48 and 54 \({}^{\circ}\)C and pH values around 4.7-5.4. ROV (remotely operated vehicle) images have enabled the discovery and location of a hydrothermal system situated southwest of the Isolotto di Basiluzzo at around 70-80 m depth, known as'smoking land', with the release of Fe-rich fluids [103] and characterized by the presence of over 200 volcanic chimneys, typically conical in shape, ranging from 1 to 4 m in height, some of which are active and emit a mixture of warm waters and gases. Of course, deep-sea areas potentially eligible for mining activities are more interesting because they are less exposed to environmental damage. In this sense, partially demagnetized sectors inside magnetic bodies are more interesting because these are the areas presumably affected by demagnetization due to the presence of hydrothermal vents. Crustal demagnetization is a common feature in basalt-hosted hydrothermal vent fields at slow- and ultra-slow-spreading mid-ocean ridges and caldera hydrothermal areas, primarily due to the removal of magnetic minerals by hydrothermal alteration processes and thermal demagnetization [104; 105]. The Palinuro Seamount (Figure 6) shows E to W morphologic changes with distinct groups of calderas (westernmost sector), cones (central sector), and dissected shapes (eastern sector; Figure 5). The Palinuro Volcanic Chain is completed by coalescent volcanic items named Glabro, Entorio, the Ovidio Seamount, and Diamante.