Emma Liu

emma-liuMy research focuses on constraining the magmatic processes during magma ascent that govern the magnitude and impact of volcanic emissions: my PhD research investigated the physical mechanisms responsible for the generation of volcanic ash, whilst my current postdoctoral work explores the chemical controls on the outgassing of sulfur and metals, and the implications for the global sulfur cycle.

Volcanic eruptions release vast quantities of ash, gas, and aerosols into the atmosphere. These emissions pose significant societal, environmental and climatic hazards that operate over a range of timescales from days to decades. Sulfur is a key volatile constituent of magmas and yet the global volcanic sulfur budget is still relative poorly constrained, at least in part due to uncertainty in the role of co-existing sulfide phases in controlling the availability of sulfur and ‘sulfur-loving’ (chalcophile) metals during magma ascent. By integrating petrological and geochemical data from erupted tephra with atmospheric measurements of SO2 and metal aerosol in volcanic plumes, my research explores the conditions under which sulfide phases scavenge and release sulfur and chalcophile metals in mafic volcanic systems, and the timescales over which this may occur. Specifically, I am investigating the extent to which the timing of sulfide formation (sulfide-saturation) relative to the onset of gas exsolution (vapour-saturation) is critical to determining whether sulfur and metals are sequestered in the crust or released, either to the atmosphere or into ore-forming fluids. My aim is to improve our understanding of the conditions that maximise sulfur (and metal) outgassing versus sulfur sequestration for different tectonic settings, accounting for the interplay between silicate melt, sulfide liquid, and magmatic vapour throughout magma ascent and crystallisation.

Working on: Holuhraun, Iceland; Volcán de Fuego, Guatemala; Grimsvötn, Iceland; Krafla, Iceland.