Mercury fluxes from hydrothermal venting at mid-ocean ridges constrained by measurements / 12.12.2023

As part of the EU MSCA ITN GMOS-Train project, coordinated by Prof. Milena Horvat from the Department of Environmental Sciences, an interesting study has been published, available in Nature Geosciences.

The significance of the study lies primarily in its use of measurements from fluids within the plume, seawater, and rock samples from the Trans-Atlantic Geotraverse (TAG) hydrothermal vent in the Mid-Atlantic Ridge. Samples were collected during specific GEOTRACES and IODP expeditions. Combined observations indicate that the majority of mercury, enriched in the vent fluids, is diluted in seawater, with only a small portion locally cleansed. Extrapolating the results suggests that the global hydrothermal flux of mercury from mid-ocean ridges is small (1.5 - 65 tons annually) compared to anthropogenic mercury emissions. While this indicates that most of the mercury in the ocean is of anthropogenic origin, it also provides hope that strict implementation of emission reductions under the Minamata Convention will decrease mercury levels in fish and human exposure.