Dissolved chromium (Cr) in the ocean is present under two oxidation states: The oxidized and soluble Cr (VI) and the reduced more reactive Cr (III). Reduction of Cr (VI) to […]
Mar / 19 / 2019
Isotopes
Using the three thorium isotope toolbox to probe the particle dynamic within an East Pacific Rise hydrothermal plume
The insoluble radiogenic isotopes of thorium (Th) are produced at a known rate in the water column via the decay of soluble uranium (234Th, 230Th) and radium (228Th) isotopes. These […]
Feb / 07 / 2019
The circulation loop in the North Atlantic and Arctic oceans depicted by the artificial radionuclides
Three articles from three cruises highlighted here! Atlantic waters have been recently recognized to play an increasing role in reducing sea-ice extent in the Arctic Ocean at a rate now […]
Jan / 30 / 2019
Cadmium isotopes, tracers of the cadmium sequestration as cadmium sulphide in oxygen minimum zone?
The linear relationship between the seawater cadmium and phosphate dissolved concentrations lead to use the cadmium/calcium (Cd/Ca) imprinted in calcareous archives to reconstruct the past phosphate (PO4) distributions. However, variations […]
Jan / 07 / 2019
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 […]
Dec / 11 / 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 […]
Dec / 10 / 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 […]
Oct / 23 / 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 […]
Oct / 19 / 2018
Environmental changes in the Arctic Ocean are occurring now!
This is what reveals the first full transarctic section of radium-228 (228Ra) in surface waters measured during Arctic cruises along GEOTRACES transects GN04 (cruise PS94) and GN01 (cruise HLY1502) proposed […]
Sep / 22 / 2018