Arctic mercury export flux with marine particles higher than anticipated

In the ocean, the residence time of mercury (Hg), is largely driven by two removal mechanisms: evasion to the atmosphere and downward export flux with settling particles. The later was particularly poorly constrained in the Arctic Ocean, as was the Hg burial rate into the sediment. Using samples collected during the German GEOTRACES TransArcII (GN04) […]

May / 06 / 2020

Why did the concentration of atmospheric carbon dioxide rise so much and so quickly during the last deglaciation? 

During the Last Glacial Maximum, the deep southern Pacific waters were stratified, efficiently accumulating old, CO2 rich waters. Basak and co-authors (2018, see reference below) measured neodymium isotopes in sediment cores that clearly show that when these deep waters became less stratified as the climate warmed they released their carbon which could escape to the […]

Mar / 06 / 2018

The sedimentary flux of dissolved rare earth elements to the ocean

This work highlights the importance of the sedimentary source of dissolved Rare Earth Elements (REE) to the oceanic waters. Indeed, strong subsurface REE concentration maxima are evidenced in pore fluids in core tops collected along the Californian and Oregon margins (above, within and below the oxygen minimum zone of the North-East Pacific). Diffusive flux of […]

Jun / 29 / 2015