EGU2020-162
https://doi.org/10.5194/egusphere-egu2020-162
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Trace element emissions during the 2018 Kilauea Lower East Rift Zone eruption

Emily Mason1, Penny Wieser1, Emma Liu2, Evgenia Ilyinskaya3, Marie Edmonds1, Rachel C W Whitty3, Tamsin Mather4, Tamar Elias5, Patricia Amanda Nadeau5, Christoph Kern6,7, David J Schneider8, and Clive Oppenheimer9
Emily Mason et al.
  • 1University of Cambridge, Department of Earth Sciences, Cambridge, UK (em572@cam.ac.uk)
  • 2University College London, Department of Earth Sciences, UK
  • 3University of Leeds, School of Earth and Environment, UK
  • 4University of Oxford, Department of Earth Sciences, UK
  • 5USGS Hawaiian Volcano Observatory, USA
  • 6USGS, Baltimore, MD, USA
  • 7USGS Cascades Volcano Observatory, USA
  • 8USGS Alaska Volcano Observatory, USA
  • 9University of Cambridge, Department of Geography, UK

The 2018 eruption on the Lower East Rift Zone of Kilauea volcano, Hawai’i released unprecedented fluxes of gases (>200 kt/d SO2) and aerosol into the troposphere [1,2]. The eruption affected air quality across the island and lava flows reached the ocean, forming a halogen-rich plume as lava rapidly boiled and evaporated seawater.

We present the at-source composition – gas and size-segregated aerosol – of both the magmatic plume (emitted from ‘Fissure 8’, F8) and the lava-seawater interaction plume (ocean entry, OE), including major gas species, and major and trace elements in non-silicate aerosol. Trace metal and metalloid (TMM) emissions during the 2018 eruption were the highest recorded for Kilauea, and the magmatic ‘fingerprint’ of TMMs (X/SO2 ratios) in the 2018 plume is consistent with measurements made at the summit lava lake in 2008 [3], and with other rift and hotspot volcanoes [4,5].

We show that the OE plume composition predominantly reflects seawater composition with a small contribution from plagioclase +/- ash. However, elevated concentrations of some TMMs (Bi, Cd, Cu, Zn, Ag) with affinity for Cl-speciation in the gas phase cannot be accounted for by the silicate correction and therefore may derive from degassing of lava in the presence of elevated Cl-. In the case of silver and copper, concentrations in the OE plume are elevated above both the F8 plume and seawater.

At-vent speciation of TMMs in the F8 plume during oxidation (following a correction for ash contributions) was assessed using a Gibbs Energy Minimization algorithm (HSC chemistry, Outotec Research). We also demonstrate the sensitivity of speciation in the plume to the concentration of common ligand-forming elements, chlorine and sulfur. These results could be used as initial conditions in atmospheric reaction models to investigate how plume composition evolves as low-temperature chemistry takes over.

References:

[1] Neal C et al. (2019) Science

[2] Kern C et al. (2019) AGU Fall meeting abstract V43C-0209

[3] Mather T et al. (2012) GCA 83:292-323

[4] Zelenzki et al. (2013) Chem Geol 357:95-116

[5] Gauthier P-J et al. (2016) J Geophys 121:1610-1630

How to cite: Mason, E., Wieser, P., Liu, E., Ilyinskaya, E., Edmonds, M., Whitty, R. C. W., Mather, T., Elias, T., Nadeau, P. A., Kern, C., Schneider, D. J., and Oppenheimer, C.: Trace element emissions during the 2018 Kilauea Lower East Rift Zone eruption, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-162, https://doi.org/10.5194/egusphere-egu2020-162, 2019

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