Distribution and behavior of dissolved hydrogen sulfide in hydrothermal plumes

Through the deep ocean, hydrothermal plumes disperse high concentrations of key chemical tracers including He-3, CH4, Mn, Fe, H2S, etc. This paper foc uses on the distribution and behavior of total dissolved sulfide (sulfide h ereafter) in hydrothermal plumes to show that its plume concentration decre ases to subnanomolar a few kilometers from the vents. We also report on sul fide removal rates determined at in situ conditions; we observe that they a re two orders of magnitude greater than for open ocean seawater, consistent with sulfide being detected only in the vicinity of hydrothermal vents. Fr om our observations, we infer that the sole presence of sulfide in hydrothe rmal plumes locates active venting at the kilometer scale.