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.


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.

Latest highlights

MOTES: a new facility designed for trace element sampling in seawater

Zhang and a group of engineers and researchers from Shanghai and Qingdao are presenting a modular trace element sampling facility.

A thorough estimate of the hydrothermal plumes on neodymium concentration and isotope oceanic cycles

Basak and co-workers investigated the influence of particulate matter on neodymium distributions in the Southern East Pacific Rise Hydrothermal Plume.

What are the drivers of the distributions of cadmium, nickel, zinc, copper and cobalt, manganese and aluminium in the Atlantic Ocean? Two papers are tackling this issue

Chen and co-authors reveal that the distributions of dissolved tracers at depth in the South Atlantic are predominantly controlled by the mixing of North Atlantic Deep Water and waters of Antarctic origin…

Disentangling the sources and transport of iron in the Southern Ocean using a water mass mixing model analysis

Traill and co-workers used an extended optimum multiparameter analysis water‐mass mixing model to determine the interplay between physical and biological processes, and sources/sinks driving dissolved iron distributions…