Mount Etna and the 1971 eruption - The collection and analysis of volcanic gases from Mount Etna

Abstract

A new method of collecting and analysing volcanic gases is described. Analyses of gases collected from Mt Etna during the restricted activity of 1970 and during the eruption of 1971 are presented. It is concluded that the most meaningful way of comparing analyses is in the atomic form as this eliminates secondary equilibration effects. The gases of 1970 and 1971 are distinguished by graphical presentation of the analyses, the main difference being their sulphur content.

H2S fluxes from Mt. Etna, Stromboli, and Vulcano (Italy) and implications for the sulfur budget at volcanoes

“…However, in the past some directly sampled chemical and isotope data have been collected, mostly at eruptive vents and/or lava flows. An estimate of Etna's magmatic gas SO 2 /H 2 S ratio at "source" (Ϸ10) was given by Huntingdon (1973), based on composition of gas samples (T Ϸ 1000°C) collected near the summit crater vents. Gerlach (1979), however, showed these gas analyses were affected by considerable non-equilibrium secondary processes due to poor sampling conditions and proposed "restored" gas compositions with a higher SO 2 /H 2 S ratio (Ϸ100).…”

A comparison of volcanic with other fluxes of atmospheric trace gas constituents

“…Kilauea, Erta'Ale, and Surtsey are far from being typical volcanoes. Huntingdon [1973] analyzed gases from Mount Etna (Sicily) during eruptions in 1970 and 1971. The 1970 collections were made at spatter cones over lava flows where the gases were issuing at about 1000øC.…”

“…Gerlach [1978] pointed out that the analysis by Huntingdon [1973] indicated the most reduced volcanic gases ever reported, and 'restored' the analysis with thermodynamic calculations. This restoration increased the concentrations of SO2.…”