Rare Earth Elements and neodymium isotopes as tracers in the Mediterranean Sea

Garcia-Solsona and co-workers (2020, see reference below) analysed 9 seawater stations around the central Mediterranean Sea (MS) to clarify the relative importance of external sources, vertical (biogeochemical) processes and lateral water mass transport in controlling Rare Earth Elements (REE) and neodymium isotopic composition (εNd) distributions.

Their results clearly identify the influence of continental input from the western Italian coast to the Tyrrhenian surface waters, marked by a negative correlation of surface light REE enrichment with offshore distance.

Contrastingly, a reasonable conservative behaviour of heavy REE and εNd is observed in the Central MS. This contrast induces a decoupling of [Nd] and εNd in all water masses of the central MS below the thermocline.  

The conservativity of heavy REE and εNd as water mass mixing tracers was successfully established using an Optimum Multi-Parameter Analysis (OMPA) and confirming that the distributions of heavy REE and εNd signals are determined by mixing of the water masses present in the region: Modified Atlantic Water (MAW), Levantine Intermediate Water (LIW), Eastern Mediterranean Deep Water (EMDW) and Western Mediterranean Deep Water (WMDW). From their results, authors further suggest that εNd helps traditional oceanographic tracers in better defining the intrusion of EMDW through the Strait of Sicily to the western Mediterranean basin.

HiRes
Figures: The bottom figure is a map of the Central Mediterranean Sea with sampled stations in coloured dots. The dashed green line indicates the NW-SE section used to display the eNd values represented in the figure above. Changes in eNd values may be ascribed to the presence of different water masses; for example, a tongue of radiogenic LIW is clearly delineated from its eastern origin to the western basin.

Reference:

Garcia-Solsona, E., Pena, L. D., Paredes, E., Pérez-Asensio, J. N., Quirós-Collazos, L., Lirer, F., & Cacho, I. (2020). Rare earth elements and Nd isotopes as tracers of modern ocean circulation in the central Mediterranean Sea. Progress in Oceanography, 185, 102340. DOI: https://doi.org/10.1016/J.POCEAN.2020.102340

Latest highlights

Science Highlights

The most important thorium-234 disequilibrium compilation you ever saw

Elena Ceballos-Romero and her colleagues propose a comprehensive global oceanic compilation of Thorium-234 measurements.

23.06.2022

Science Highlights

Machine learning approach led to the first iron climatology

Huang and co-workers propose the first data-driven surface-to-seafloor dissolved iron climatology.

21.06.2022

Science Highlights

Insight on the aluminium cycling during the inter-monsoon period in the Arabian Sea and Equatorial Indian Ocean

Full vertical water column profiles were established by Singh and Singh along the GI05 transect in the Indian Ocean during the fall inter-monsoon period in 2015.

Science Highlights

Distributions, boundary inputs, and scavenging processes of trace metals in the East Sea (Japan Sea)

Seo and his colleagues show pronounced atmospheric and shelf inputs of trace elements in the Japan Sea.

14.06.2022

Rechercher