biostudies-literatureUnknown8(1)Loher MSubmarine mud volcanoes release sediments and gas-rich fluids at the seafloor via deeply-rooted plumbing systems that remain poorly understood. Here the functioning of Venere mud volcano, on the Calabrian accretionary prism in ~1,600 m water depth is investigated, based on multi-parameter hydroacoustic and visual seafloor data obtained using ship-borne methods, ROVs, and AUVs. Two seepage domains are recognized: mud breccia extrusion from a summit, and hydrocarbon venting from peripheral sites, hosting chemosynthetic ecosystems and authigenic carbonates indicative of long-term seepage. Pore fluids in freshly extruded mud breccia (up to 13 °C warmer than background sediments) contained methane concentrations exceeding saturation by 2.7 times and chloride concentrations up to five times loweScientific reports6275https://www.ebi.ac.uk/biostudies/studies/S-EPMC5908856biostudies-literatureMud extrusion and ring-fault gas seepage - upward branching fluid discharge at a deep-sea mud volcano.PMC5908856Romer MTorres MLoher MPraeg DBohrmann GPape TWintersteller PSahling HMarcon YfalseMud extrusion and ring-fault gas seepage - upward branching fluid discharge at a deep-sea mud volcano.Submarine mud volcanoes release sediments and gas-rich fluids at the seafloor via deeply-rooted plumbing systems that remain poorly understood. Here the functioning of Venere mud volcano, on the Calabrian accretionary prism in ~1,600 m water depth is investigated, based on multi-parameter hydroacoustic and visual seafloor data obtained using ship-borne methods, ROVs, and AUVs. Two seepage domains are recognized: mud breccia extrusion from a summit, and hydrocarbon venting from peripheral sites, hosting chemosynthetic ecosystems and authigenic carbonates indicative of long-term seepage. Pore fluids in freshly extruded mud breccia (up to 13 °C warmer than background sediments) contained methane concentrations exceeding saturation by 2.7 times and chloride concentrations up to five times lowe2018-01-01T00:00:00Z2018 Apr2025-04-04T14:01:47.426Z2019-03-26T23:36:15ZS-EPMC59088562967464910.1038/s41598-018-24689-1