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.

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.


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

Different fates of four poorly soluble trace elements in the Pacific Ocean

Zheng and co-authors present the full-depth distributions of aluminum, lead, manganese and copper in the western South Pacific.


Science Highlights

Internal tides, energetic dynamical processes that generate particle nepheloids at different depths

In this study, Barbot and co-authors identified the sites where internal tides are responsible for sediment resuspension…


Science Highlights

Greenland’s floating ice tongues, sources of dissolved lead to the Arctic

Using helium and neon as tracers for subglacial meltwater, Krisch and colleagues found that subglacial discharge is a source of dissolved lead.

Science Highlights

Shelf sediments in the Benguela Upwelling System as a major source of trace metals to the shelf and eastern South Atlantic Ocean

Liu and her colleagues investigated dissolved trace metals distributions within the Benguela Upwelling System sampled from GEOTRACES GA08 cruise.