[S-GC37] Volatiles in the Earth - from Surface to Deep Mantle

[SGC37-06] Project COESS and the tracing of seafloor volatiles: An action plan for the UN Decade of Ocean Science for Sustainable Development

★Invited Papers

*Glen Snyder¹, Ryo Matsumoto², Hitoshi Tomaru³, Fumito Shiraishi⁵, Shiono Miki¹, Yuji Sano⁴, Ma Teresa Nakajima¹ (1.Atmosphere and Ocean Research Institute, University of Tokyo, 2.Gas Hydrate Research Laboratory, Meiji University, 3.Department of Earth Sciences, Chiba University, 4.Center for Advanced Marine Core Research, Kochi University, 5.Earth and Planetary Systems Science Program, Hiroshima University)

Keywords:Cold Seeps, Hydrothermal Vents, Seep Ecology, UN Ocean Decade, Seafloor Gas Emissions

Project COESS (Chemistry, Observation, and Ecology of Submarine Seeps) was established in 2022 and formally endorsed by UNESCO as part of the United Nations Decade of Ocean Science for Sustainable Ocean Development. The purpose of the project is to study and promote public awareness of ecosystems related to submarine seep environments found along the coastal margins of Japan. The project currently involves 14 researchers from 10 different Japanese Institutions and intends to carry out research activities related to both hydrocarbon seeps and hydrothermal vents. As increasing pressure is placed on these environments and their exploitation as offshore economic resources, relatively little is known about the ecosystems associated with them and their role in the larger marine biosphere. This project will involve the deployment of instrumentation to determine both the baseline and long-term variability in seep and vent activity. Previous investigations of these seep environments have shown varying degrees of volatile contribution from mantle, crustal, and sedimentary sources, with both biogenic and thermogenic methane sources. By collecting time-series data, we aim to show how these different components change over time in response to seismic and other physical variables. The contribution of seafloor seep emissions to gas transfer at the ocean/atmosphere interface will also be investigated. Support for this project has been provided in part by Fugro USA. Fugro is an official partner of the UN Ocean Decade.