Gamma spectroscopy studies of the underwater hydrothermal vent field of the Methana Peninsula

Abstract

A preliminary study of natural radioactivity was conducted on the thermal spas in Methana Peninsula. To carry out this research, a collection of 17 water samples were taken from thermal springs around and underwater of the volcanogenic Peninsula at depths ranging 0–5 m. The Methana peninsula belongs to the Hellenic Volcanic Arc and is characterized by hydrothermal vent activity. A NaI(Tl) scintillator (AMESOS) was used to carry out gamma–ray counting of the samples to deduce the activity concentrations of the natural radionuclides of the ²³⁸U and ²³²Th decay series, as well as ⁴⁰K in spa waters. Results are expected to provide information on the geological setting of the Methana peninsula. The impact of naturally occurring radioisotopes to human health has also been assessed in terms of the radiation dose risk corresponding to the measured activities.