%0 Journal Article %T The remarkable longevity of submarine plumes: Implications for the hydrothermal input of iron to the deep-ocean %+ Institut de Physique du Globe de Paris (IPGP) %A Carazzo, G. %A Jellinek, A. M. %A Turchyn, A. V. %< avec comité de lecture %@ 0012-821X %J Earth and Planetary Science Letters %I Elsevier %V 382 %P 66-76 %8 2013 %D 2013 %Z 2013E&PSL.382...66C %R 10.1016/j.epsl.2013.09.008 %Z Sciences of the Universe [physics]Journal articles %X The longevity of submarine plumes generated at sea-floor hydrothermal systems constrains the hydrothermal input of chemical species into the deep-ocean. Decades of observations of episodic “event plumes” suggest that a key process governing the dynamics of an hydrothermal cloud spreading out laterally from a buoyant rising plume is the production of internal layering. Here, we use analog experiments on turbulent, hot particle-laden plumes and clouds to show that this layering occurs where particle diffusive convection driven by the differential diffusion of heat and small mineral precipitates gives rise to a large scale double diffusive instability. Where hydrothermal clouds are enriched in fine minerals, this “particle diffusive convection” can extend the longevity of an event plume to 2 yr after its emplacement. The very long residence time imposed by diffusive convective effects enables complete dissolution of fine sulfide and sulfate minerals. We develop a new theoretical model that includes both sedimentation and dissolution processes to quantify the potential amount of iron produced by the dissolution of iron-sulfide minerals settling through the cloud by diffusive convection. A key prediction is that the concentration of dissolved iron in hydrothermal clouds can reach up to 19±3 nM, which represents about 5% of the global hydrothermal discharge. If these results are representative of all hydrothermal vent fields, hydrothermal systems could provide 75% of the global budget of dissolved iron in the deep-ocean. Regionally, this flux is expected to scale in magnitude with mid-ocean ridge heat flow, consistent with observations and global ocean models. %G English %L insu-03581757 %U https://insu.hal.science/insu-03581757 %~ INSU %~ UNIV-PARIS7 %~ AFRIQ %~ CNRS %~ IPGP %~ SORBONNE-UNIVERSITE %~ UNIV-PARIS %~ ALLIANCE-SU