convener:Yusuke Miyajima(Geomicrobiology Research Group, Research Institute for Geo-Resources and Environment, Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology), Tomohiro Toki(Faculty of Science, University of the Ryukyus), Robert Jenkins(School of Geosciences and Civil Engineering, College of Science and Engineering, Kanazawa University), Akira Ijiri(Japan Agency for Marine-Earth Science and Technology)

Mud volcanoes transport fluids and sediments from the deep subsurface to the Earth's surface and form topographic features. Mud volcanoes play a role in material cycling connecting the underground and surface, pipe of life in depth, emissions of methane leading to environmental change, and natural disasters. However, the formation mechanism, activity, and spatiotemporal distribution of mud volcanoes are not well-understood. On the summit of submarine mud volcanoes, chemosynthetic communities are sustained by energy produced from methane and hydrogen sulfide contained in the transported fluid. Chemosynthetic communities are distributed in extreme environments such as deep-sea hydrothermal vents, mud volcanoes, and/or cold seeps and have changed their taxonomic composition and spatial distribution through the Earth history. However, the causes and background of their evolution remain unclear.
This session aims to reveal interactions between geosphere and biosphere from the past to the present and in the future through investigations on mud volcanoes as "windows to subsurface environments" and chemosynthetic communities as "ecosystems sustained by geofluid". We welcome not only studies focusing on either fluid-flow systems including mud volcanoes, cold seeps, and hydrothermal vents, or biological communities depending on them, but also cross-cutting contributions combining biological, geochemical, geological, or geophysical methods. Talks and discussions in this session will be held in Japanese, though presentation slides may be prepared in English.