Silicon isotopes reveal the different Arctic endmembers contributing to the deep water formed in the North Atlantic Ocean

Combining a multiparametric analysis, biogenic and dissolved silicon (Si) isotope data (30Si-bSiO2 and δ30Si-DSi, respectively) in the Arctic Ocean, Liguori and co-workers (2020, see reference below) could unravel the influence of water masses on the δ30Si-DSi distribution within the Arctic Ocean. Any deviation of the δ30Si-DSi signature from pure mixing was attributed to the contribution […]

Apr / 20 / 2020

Dissolved zinc and silicate decoupling in the North Pacific Ocean

Large-scale distributions of dissolved zinc (Zn) in the western and central subarctic North Pacific Ocean was established as part of the North Pacific GEOTRACES section GP02. Kim and co-workers could figure out interesting Zn behavior in this area: Decoupling between Zn and Silicate in the intermediate water, Zn* values (used to show the variability in […]

Dec / 13 / 2017

GEOTRACES intercalibration of the stable silicon isotope composition of dissolved silicic acid in seawater

Dissolved silicon (Si) is a major oceanic nutrient and variations of its stable isotope values are reflecting the intensity of surface primary production. As for other isotopes, agreement between the different laboratories is crucial. Here, the first intercalibration study of the stable silicon (Si) isotopes in seawater (δ30Si(OH)4) is presented as a contribution to the […]

Apr / 14 / 2017

The coupled zinc-silicon cycle paradox illuminated

The strong similarities between zinc (Zn) and silicon (Si) vertical profiles have led many studies to suggest the uptake of Zn in diatom frustules, followed by simultaneous remineralisation at depth. However, recent lab experiments have demonstrated that Zn, although essential for diatoms, is located in the organic part of the cell. These cells are characterized […]

Feb / 08 / 2017

Amazingly detailed compilation of the silicon cycle, with an emphasis on the oceanic silicon isotope budget

Although this article is not resulting from GEOTRACES activity, its content is definitely GEOTRACES relevant. The authors constructed an up-to-date compilation of the continental silicon (Si) cycle, including the fate of Si isotopic composition in the different continental but also estuarine and marine solid and solutions. This is a paper highly recommended by Catherine Jeandel, […]

May / 09 / 2016

First major ocean sections of silicon isotopes

The GEOTRACES programme is providing the first major ocean sections of silicon isotopes, δ30Si, aiding efforts to use this proxy to reconstruct diatom silica production in both the modern and paleo ocean. In the May, 2015 issue of Global Biogeochemical Cycles Holzer and Brzezinski explore the links between δ30Si within silicic acid and the meriodional […]

Jun / 08 / 2015

What drives the silicon budget in the Bay of Bengal? The isotope composition clues…

The first data set of dissolved silicon isotope composition (δ30Si) along with concentrations (DSi) in seawater of the northern Indian Ocean is presented from the Bay of Bengal (BoB) region. Elevated Si (>3 µmol/kg) in surface waters of coastal stations indicates the continental supply, whereas a spike of Si (~30 µmol/kg) and a salinity maxima […]

Feb / 12 / 2015