Abstract

Sulfur emissions from volcanoes influence Earth’s climate, have profound effects on the local environment and human health during volcanic eruptions, and provide a tool to monitor volcanic activity from space. How much sulfur is released during volcanic eruptions is a complex interplay of magma storage pressure, temperature, melt sulfur content, and melt redox state. Sulfur isotope fractionation during sulfur degassing and sulfide saturation provides information on the fate of sulfur in magmatic systems. Sulfur isotopes ratios measured in melt inclusions and glasses in oxidised magmas from ocean islands and arc magmas can help to constrain sulfur speciation in the gas and melt during melt evolution, and how changes in redox can influence where sulfur ends up in magmatic systems.