Volcanic and non-volcanic fluid emissions: data from EMODnet Geology

Abstract

The European Marine Observation and Data Network (EMODnet) is a network of organizations supported by the EU’s integrated maritime policy. These organizations work together to observe the sea, process the data according to international standards and make that information freely available as interoperable data layers and data products (accessible from www.emodnet.eu). It is subdivided into Lots concerning Bathymetry, Geology, Biology, Chemistry, Physics, Seabed Habitats and Human activities. The Geology Lot (www.emodnet-geology.eu) is carried out by a consortium of Geological Surveys and includes data on seafloor sediments grainsize, sedimentation rates, Quaternary geology, pre‐Quaternary geology and stratigraphy, coastal behaviour, geological events, mineral resources, submerged landscapes. Datasets available from the “Geological events and probabilities” layers, coordinated by the Geological Survey of Italy – ISPRA, include submarine landslides, earthquakes, volcanic centers, tsunamis, fluid emissions and Quaternary faults. Data gathered by Partners have been conveyed into single Europe-wide shapefiles, complemented by detailed attribute tables. Mud-volcanoes and fluid emissions of non-volcanic origin have been initially considered separately from volcanic emission, in order to prevent overlaps and confusion, because terms adopted to describe morphological types of mud-volcanoes, especially in the Black Sea, are the same used for magmatic structures. However, during later phases of the project, with increasing resolution and scale of representation, all types of fluid emissions have been gathered together in the same layer. The major component of volcanic fluid emissions is CO2, while the major component of non-volcanic fluid emissions is methane. These latter have been characterized by type, height, region, composition, morphological and activity types, age of activity. Part of the Italian results has been collected into monographs published by the Geological Survey of Italy, one dedicated to a systematic inventory of submerged volcanic structures (D’Angelo et al., 2019) and one collating contributions on occurrences of fluid emissions (D’Angelo et al., 2020) which is presented in the workshop on september 13th. In the volume dedicated to volcanoes, hydrothermal occurrences are reported wherever information is available. A specific focus is dedicated to mineral deposits associated with fluid emissions in the southern Tyrrhenian Sea and highlights the widespread occurrence of sulfate and sulfide minerals in the surroundings of volcanic structures.