Icebergs as sources of trace metals to the ocean: which impact?

Earth’s Ice Sheets are known to release significant quantities of lithogenic particles into the ocean every year, but how does this material affect trace metal availability in the ocean? Combining results from GEOTRACES cruise GN05 at the ‘79° N Glacier’ with inshore work in Greenland and the Western Antarctic Peninsula, Krause et colleagues (2021, see reference below), present trends in dissolved iron, cobalt, nickel and copper across the glacier-to-ocean salinity gradient. Elevated signals of all metals are associated with glacier runoff, although ~98% of dissolved iron supplied from freshwater is rapidly returned to particulate phases. Curiously, dissolved iron concentrations in particular appeared to be strongly buffered in inshore waters throughout spring and summer, which means lateral fluxes from fjord over-turning may be a key driver of lateral trace element export year-round.

Figure: Field locations and sample collection points: Trace metal concentrations across the salinity gradient were sampled at 8 sites spanning Greenland and the Western Antarctic Peninsula.

Reference:

Krause, J., Hopwood, M. J., Höfer, J., Krisch, S., Achterberg, E. P., Alarcón, E., Carroll, D., González, H. E., Juul-Pedersen, T., Liu, T., Lodeiro, P., Meire, L., Rosing, M. T. (2021). Trace Element (Fe, Co, Ni and Cu) Dynamics Across the Salinity Gradient in Arctic and Antarctic Glacier Fjords. Frontiers in Earth Science, 9, 878. https://doi.org/10.3389/feart.2021.725279

Latest highlights

Coupling copper and neodymium data highlights the importance of the margin sources for the copper oceanic cycle

Lemaitre and co-workers analysed the dissolved concentrations and isotopes along the GEOVIDE (GA01) section in the North Atlantic Ocean.

High levels of anthropogenic lead in the Indian Ocean

Yadav and her colleagues provide comprehensive insights into the distribution and sources of dissolved lead in the Indian Ocean.

Elevated methylmercury level in Arctic rain and aerosol linked to oceanic dimethylmercury emissions

He and colleagues highlight a previously underappreciated pathway of mercury transport, underscoring its significance to human health.

Unveiling the Complexity of Lead Distribution in the Pacific Ocean: Insights from the GEOTRACES GP15 Transect

This recent study by Jiang and colleagues investigates the distribution and sources of lead in the Pacific Ocean.

Rechercher