Radium isotopes in seawater, suspended and sinking particles collected at DYFAMED station (Western Mediterranean Sea)
We measured 226Ra and 228Ra activities in seawater, suspended and sinking particles collected at the DYFAMED station in the Western Mediterranean Sea (BARMED program). Measurements were made by gamma counting at the underground laboratory of Modane in the French Alps. 228Ra/226Ra ratios were used to track the origin and fate of barite (BaSO4) crystals in the water column. We also show that the 228Ra/226Ra ratios in particles can provide information on aggregation/ disaggregation processes. Additionally, we investigated the possibility of measuring both 224Ra and 223Ra activities - that are used to trace submarine groundwater discharge - by gamma spectrometry. Radium isotopes were thus i) separated from water samples collected in the Vaccarès pond using either MnO2 fiber or BaSO4 co-precipitation and ii) measured using either RadeCC (alpha spectrometry) or gamma spectrometry at the underground laboratory of Modane.
HyMeX – Hydrological cycle in the Mediterranean Experiment 2010-2020