Composition-resolved size distributions of volcanic aerosols in the Mt. Etna plumes

Martin, RS.; Mather, TA.; Pyle, DM.; Power, M.; Allen, AG.; Aiuppa, A.; Horwell, CJ.; Ward, EPW.

Abstract

Particle size distributions for soluble and insoluble species in Mt Etna’s summit plumes were measured across an extended size range (10 nm < d < 100 ìm) using a combination of techniques. Automated scanning electron microscopy (QEMSCAN) was used to chemically analyze many thousands of insoluble particles (collected on pumped filters) allowing the relationships between particle size, shape and composition to be investigated. The size distribution of fine silicate particles (d < 10 ìm) was found to be lognormal, consistent with formation by bursting of gas bubbles at the surface of the magma. The compositions of fine silicate particles were found to vary between magmatic and nearly-pure silica; this is consistent with depletion of metal ions by reactions in the acidic environment of the gas plume and vent. Measurements of the size, shape and composition of fine silicate particles may potentially offer insights into pre-, syn- and post- emission processes. The mass flux of fine silicate particles from Mt Etna released during non-eruptive volcanic degassing in 2004 and 2005 was estimated to be ~7000 kg d-1. Analysis of particles in the range 0.1 < d/ìm < 100 by ion chromatography shows that there are persistent differences in the size distributions of sulfate aerosols between the two main summit plumes. Analysis of particles in the range 0.01 ìm < d < 0.1 ìm by scanning transmission electron microscopy (STEM) shows that there are significant levels of nanoparticles in the Mt Etna plumes although their compositions remain uncertain.

Citation

Martin, R., Mather, T., Pyle, D., Power, M., Allen, A., Aiuppa, A., …Ward, E. (2008). Composition-resolved size distributions of volcanic aerosols in the Mt. Etna plumes. Journal of Geophysical Research, 113, https://doi.org/10.1029/2007jd009648

• Journal Article Type: Article
• Publication Date: 2008
• Journal: Journal of Geophysical Research
• Print ISSN: 0148-0227
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 113
• DOI: https://doi.org/10.1029/2007jd009648