Submarine groundwater discharge investigations in Sicilian and Brazilian coastal waters using an underwater gamma-ray spectrometer

Abstract Submarine groundwater discharge (SGD) in coastal zones was monitored using in situ underwater gamma-ray spectrometry of radon decay products ( 214 Bi). Several sites were visited during the IAEA'2002 expedition to south-eastern Sicily, where SGD variations were observed in the Donnalucata boat basin. The continuous monitoring carried out for 3 days at the site closest to the coast revealed an anticorrelation dependence of 222 Rn concentration with tide and salinity. The 222 Rn activity concentrations in seawater varied from 2.3 kBq m −3 (during high tides) to 4.8 kBq m −3 (during low tides). In situ gamma-ray spectrometric measurements were also carried out during the IAEA–UNESCO'2…