Volcanic ash is the material produced by explosive volcanic eruptions that is <2 mm in diameter. Fine ash is <0.063 mm; coarse ash is from 0.063 to 2 mm.
Volcanic ash is formed during explosive volcanic eruptions. Explosive eruptions occur when magma decompresses as it rises, allowing dissolved volatiles (dominantly H2O and CO2) to exsolve into gas bubbles. These expand the fluid magma into foam and accelerate its ascent to the surface. A magmatic eruption occurs when the foamy magma fragments at the volcanic vent, with violently expanding gas bubbles tearing the silicate lattice apart to erupt into the atmosphere, where it then solidifies into fragments of volcanic rock and glass (Figure 1). Ash can also be produced when rising magma contacts water (e.g., surface water, groundwater, snow, and ice). The water explosively flashes into steam, causing shattering of the magma and resulting in a phreatomagmatic eruption. A single ...
- Cronin, SJ, Neall, VE, Lecointre, JA, Hedley, MJ, Loganathan, P (2003) Environmental hazards of fluoride in volcanic ash: a case study from Ruapehu volcano, New Zealand. Journal of Volcanology and Geothermal Research 121: pp. 271-291
- Delmelle, P, Lambert, M, Dufrêne, Y, Gerin, PA, Óskarsson, O (2007) Gas/aerosol-ash interaction in volcanic plumes: new insights from surface analysis of fine ash particles. Earth and Planetary Science Letters 259: pp. 159-170
- Heiken, G, Wohletz, KH (1985) Volcanic Ash. University of California Press, Berkeley
- Horwell, CJ, Baxter, PJ (2006) The respiratory health hazards of volcanic ash: a review for volcanic risk mitigation. Bulletin of Volcanology 69: pp. 1-24
- Johnston, DM, Houghton, BF, Neall, VE, Ronan, KR, Paton, D (2000) Impacts of the 1945 and 1995–1996 Ruapehu eruptions, New Zealand: An example of increasing societal vulnerability. Geological Society of America Bulletin 112: pp. 720-726
- Pyle, DM (1989) The thickness, volume and grain size of tephra fall deposits. Bulletin of Volcanology 51: pp. 1-15
- Sigurdsson, H, Houghton, B, Rymer, H, Stix, J (2000) Encyclopedia of Volcanoes. Academic, San Diego
- Stewart, C, Johnston, DM, Leonard, GS, Horwell, CJ, Thordarson, T, Cronin, SJ (2006) Contamination of water supplies by volcanic ash fall: A literature review and simple impact modelling. Journal of Volcanology and Geothermal Research 158: pp. 296-306
- Wilson, T. M., Cole, J. W., Cronin, S. J., Stewart, C., and Johnston, D. M., 2010. Impacts on agriculture following the 1991 eruption of Vulcan Hudson, Patagonia: Lessons for Recovery. Natural Hazards, doi 10.1007/s11069-010-9604-8.
- Witham, CS, Oppenheimer, C, Horwell, CJ (2005) Volcanic ash leachates: a review and recommendations for sampling methods. Journal of Volcanology and Geothermal Research 141: pp. 299-326
- Volcanic Ash
- Reference Work Title
- Encyclopedia of Natural Hazards
- pp 1074-1076
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- Encyclopedia of Earth Sciences Series
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- Springer Netherlands
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- Springer Science+Business Media Dordrecht
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- 1. Simon Fraser University
- Author Affiliations
- 00371. Department of Geological Sciences, University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand
- 00372. Joint Centre for Disaster Research, GNS Science/Massey University, Wellington Campus, 756, New Zealand
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