Submarine hydrothermal vents are important sources of trace metals that can influence oceanic biogeochemistry. Trace metals from hydrothermal vents are rapidly precipitated during seafloor venting, and precipitation continues as non-buoyant hydrothermal plumes are transported to depths of ~ 2000 - 3000 m. We conducted a multidisciplinary scientific cruise in the Northeast Indian Ocean and collected seawater samples for noble gases, dissolved gases, trace metals and their isotopes, and nutrients. Noble gas isotopes (e.g. ³He) will be used to assess the conservative and non-conservative behaviour of trace metals during seafloor venting and lateral transport in hydrothermal plumes. Analyses of trace metals in both dissolved and particulate phases will help us to understand the evolution and migration of trace metals between different pools. We will then estimate the gross input of trace metals from hydrothermal vents, the sink of trace metals during seafloor venting and plume transport, and the net input of trace metals from hydrothermal vents to the open ocean.

hydrothermal vents, trace metals, hydrothermal plume