A Geochemical Study of Iodine in Volcanic Gases

Abstract

Abstract Volcanic gases from several active volcanoes in Japan have been analyzed for iodine and chlorine: Showashinzan (I=0.025–0.20 mg.I/kg.H2O, Cl=238–1830 mg.Cl/kg.H2O), Iwatesan (I=0.053–0.19, Cl=2720–3360), Issaikyoyama (I=0.030–0.087, Cl=104–213), Nasudake (I=0.16–3.9, Cl=188–9460), Yakedake (I=0.58–0.93, Cl=1250–1730), Kuju-Ioyama (I=0.13–1.3, Cl=266–8000), Kirishima-Ioyama (I=0.036–0.84, Cl=200–4200), and Miharayama (I=0.45–1.5, Cl=1640–2180). Each volcano has a characteristic I/Cl ratio. Analyses have also been made of hot-spring waters from the environs of Nasudake, Kuju-Ioyama, and Kirishima-Ioyama. It is indicated that the hot-spring waters are similar in I/Cl ratio to the volcanic gases from the same area.