Prediction of eruptions using changes in composition of volcanic gases

During observations on the dynamics and on the regime of fumarolic activity of some active volcanoes of Kamchatka and Kurile islands, a very close relation was noted between the S/Cl ratio in the fumarolic gases and in waters and the state of the volcano. The S/Cl ratio increased prior to the eruptions of Sheveluch, Bezymianny, Kluchevskoi, Zavaritsky and Ebeko volcanoes.