19 research outputs found
Occurrence and transformation of mercury in formerly contaminated soils due to operation of amalgamation techniques and assessment of consequences
Hydrochemical and atmochemical mercury dispersion zones over hydrothermal vents of the submarine Piip Volcano in the Bering Sea
Mercury in the sea water of the Amur Bay (the Sea of Japan): Recent content and geochemical processes
Gaseous Elemental Mercury Level and Distribution in a Heavily Contaminated Site: the Ex-chlor Alkali Plant in Torviscosa (Northern Italy)
A 200 km-long mercury contamination of the Paglia and Tiber floodplain: Monitoring results and implications for environmental management
Evaluation of possible impact on human health of atmospheric mercury emanations from the Popocatépetl volcano
Effect of deep Southwestern Subtropical Atlantic Ocean circulation on the biogeochemistry of mercury during the last two glacial/interglacial cycles
During glacial/interglacial cycles, changes in the strength of the Atlantic Meridional Overturning Circulation (AMOC) modified the intermediate and deep-water mass proportions and high latitude productivity in the Atlantic Ocean. These factors influence the distribution and geochemical partitioning of trace metals in the ocean. Mercury is a redox and productivity-sensitive trace metal, making it a potential proxy of paleoenvironmental changes. Therefore, this work examines the effect of Atlantic Ocean circulation changes during the last two glacial/interglacial cycles on the biogeochemistry of Hg. For this, a high-resolution record of the total Hg concentration was determined in core GL-1090 collected from the Southwestern Subtropical Atlantic that represents the last 185 thousand years. During the reported glacial/interglacial cycles, Hg showed a distinct trend throughout Marine Isotope Stages with higher concentrations during periods of enhanced penetration of northern component water into the southwestern Atlantic. This is supported by the similarity of mercury variability with benthic foraminifera δ13C, suggesting a strong influence of deep ocean circulation on the availability and accumulation of this metal in deep-sea sediments. Mercury geochemistry and particle scavenging were correlated with organic matter (OM) input at the core site. We also noted that mercury responded to redox variation in sediment after Termination II, which can be explained by the increase in deep ocean ventilation due to AMOC strengthening. This hypothesis was confirmed by the antiphase behavior of Hg and Total Organic Carbon when compared with Mn/Al ratios and CaCO3. Our work, therefore, allows for a better understanding of the processes leading to long-term mercury removal to sediments