New beautiful results on marine particle speciation, a challenge for the GEOTRACES community…

Science Highlights

3 December 2012

Advanced Light Source x-ray spectromicroscopy (XANES) allows a fine description of the marine Fe pool chemical speciation and mineralogy. This work describes diverse arrays of iron particles (20- 700 nm), showing impressive variations in the oxidation state and composition of these iron particles between the coasts of South Africa and Antarctica. Moreover, different iron pools are occurring in different frontal zones. Because particle speciation is directly linked to the element solubilities, these differences may affect the production of bioavailable dissolved iron.

Iron_particle_speciation

Source : Science (click on the image to view it larger)

Reference:

B. P. von der Heyden, A. N. Roychoudhury, T. N. Mtshali1, T. Tyliszczak, S. C. B. Myneni. (2012). Chemically and Geographically Distinct Solid-Phase Iron Pools in the Southern Ocean: Science 338 (6111): 1199-1201, DOI: 10.1126/science.1227504

Latest highlights

Continuous record of the Antarctic Circumpolar Current latitude over the last glacial-interglacial cycles

The meridional positions of the oceanic fronts separating subtropical and Antarctic waters are key to constraining the mechanisms that drive the degassing of deeply-stored CO2 at the end of the glacial periods…

23 Million Years of iron sources reconstructed in the Northwest Pacific Ocean using iron isotopes in a ferromanganese crust

Using iron isotopes and elemental records, Chu and co-workers analysed an iron-manganese crust recovered from the Hongyan Seamount, and reconstructed the sources of dissolved Fe to the Northwest Pacific Ocean…

Variability of the past deep-water masses in the Arabian Sea over the last 41ka

Shukla and colleagues propose a high-resolution authigenic ƐNd record measured from a sediment core located in the eastern Arabian Sea…

Arctic outflows to Davis Strait and the Labrador Sea traced by radionuclide distributions

This study demonstrates that Arctic outflows through the Canadian Arctic Archipelago play a much more significant role than previously recognised.

Rechercher