Gas composition of the January 1983 eruption of Kilauea Volcano, Hawaii

Gas collections were made from a ∼900°C vent both by conventional evacuated-bottle/wet-chemical techniques and by manual pumping of flowthrough bottles. The complete analyses suggest an equilibrium assemblage quenched at 1,010°C, about midway between fountain and vent temperatures. I suggest that the very low CS ratio is due to degassing of CO₂ during storage of the magma in a shallow reservoir before eruption. The two sampling techniques yielded analytical data in mutual agreement.