Science Highlights

Some recent GEOTRACES science findings are reported below.

Local geologies imprint the Antarctic Bottom Water neodymium isotopic signatures

Dissolved neodymium (Nd) isotopes and concentrations were measured at six stations in the Australian sector of the Southern Ocean, targeting the study of the Adelie Land Bottom Water (ALBW), a […]

11.12.2018

More realistic oceanic particle field improved the thorium-230 and protactinium-231 modeling

Thorium-230 (230Th) and protactinium-231 (231Pa) are two geochemical tracers extensively used for investigating particle transport in the ocean and reconstructing past ocean circulation. A key feature in reproducing their distributions by […]

10.12.2018

The residence times of trace elements determined in the surface Arctic Ocean during the 2015 US Arctic GEOTRACES expedition

Data collected during the US Arctic GEOTRACES expedition in 2015 (along GEOTRACES section GN01) were used to estimate the mean residence time of dissolved trace elements (iron-Fe, manganese-Mn, nickel-Ni, cadmium-Cd, […]

15.11.2018

Ever wonder how long your favourite element remains in the ocean before it’s gone again?

This timeframe, sometimes called a residence time, ranges from decades for the most reactive trace elements to millions of years for the most unreactive elements such as the major components […]

Methylmercury subsurface maxima explain mercury accumulation in Canadian Arctic marine mammals

Mercury (Hg) concentrations in Canadian Arctic marine mammals were monitored during the last four decades and found to be highly elevated, frequently exceeding toxicity thresholds. Mercury concentrations in marine biota […]

05.11.2018

Cadmium to phosphorus ratio in euphotic zone particulates: why does it vary?

Bourne and co-workers examine the particulate cadmium to phosphorus ratio (Cd/P) variations of 3 particle fractions (<1µm, 1-51µm and >51µm) from 50 casts covering spatial and temporal scales never reached so far […]

01.11.2018

Helium-3 plumes in the deep Indian Ocean confirm hydrothermal activity

Thanks to samples collected as part of the Japanese GEOTRACES cruise in 2009 – 2010, along section GI04, Takahata and co-workers (2018, see reference below) identified a maximum helium-3 ratios […]

23.10.2018

The role of melting-ice in driving the slowdown of circulation in the western Atlantic Ocean revealed by protactinium-thorium ratio

Abrupt climate changes in the past have been attributed to variations in Atlantic Meridional Overturning Circulation (AMOC) strength. Knowing the exact timing and magnitude of the AMOC shift is important […]

19.10.2018

52 years of Benthic Nepheloid Layer data!

A data base of 2412 profiles collected using the Lamont Thorndike nephelometer from 1964 to 1984 is used to globally map turbid nepheloid layers by Gardner and co-workers (2018, see […]

04.10.2018

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