Volcanic ash fall hazard and risk

S. F. Jenkins, T. Wilson, C. Magill, V. Miller, C. Stewart, R. Blong, W. Marzocchi, M. Boulton, C. Bonadonna, A. Costa

    Research output: Chapter in Book/Report/Conference proceedingChapter

    32 Citations (Scopus)
    480 Downloads (Pure)

    Abstract

    All explosive volcanic eruptions generate volcanic ash, fragments of rock that are produced when magma or vent material is explosively disintegrated. Volcanic ash is then convected upwards within the eruption column and carried downwind, falling out of suspension and potentially affecting communities across hundreds, or even thousands, of square kilometres. Ash is the most frequent, and often widespread, volcanic hazard and is produced by all explosive volcanic eruptions. Although ash falls rarely endanger human life directly, threats to public health and disruption to critical infrastructure services, aviation and primary production can lead to potentially substantial societal impacts and costs, even at thicknesses of only a few millimetres. Communities exposed to any magnitude of ash fall commonly report anxiety about the health impacts of inhaling or ingesting ash (as well as impacts to animals and property damage), which may lead to temporary socio-economic disruption (e.g. evacuation, school and business closures, cancellations). The impacts of any ash fall can therefore be experienced across large areas and can also be long-lived, both because eruptions can last weeks, months or even years and because ash may be remobilised and re-deposited by wind, traffic or human activities.

    Given the potentially large geographic dispersal of volcanic ash, and the substantial impacts that even thin (a few mm in thickness) deposits can have for society, this chapter elaborates upon the ash component of the overviews provided in Chapters 1 and 2. We focus on the hazard and associated impacts of ash falls; however, the areas affected by volcanic ash are potentially much larger than those affected by ash falling to the ground, as fine particles can remain aloft for extended periods of time. For example, large portions of European airspace were closed for upto five weeks during the eruption of Eyjafjallajökull, Iceland, in 2010 because of airborne ash (with negligible associated ash falls outside of Iceland). The distance and area over which volcanic ash is dispersed is strongly controlled by wind conditions with distance and altitude from the vent, but also by the size, shape and density of the ash particles, and the style and magnitude of the eruption. These factors mean that ash falls are typically deposited in the direction of prevailing winds during the eruption and thin with distance. Forecasting ash dispersion and the deposition ‘footprint' is typically achieved through numerical simulation.
    Original languageEnglish
    Title of host publicationGlobal volcanic hazards and risk
    EditorsSusan C. Loughlin, Steve Sparks, Sarah K. Brown, Susanna F. Jenkins, Charlotte Vye-Brown
    Place of PublicationCambridge, UK
    PublisherCambridge University Press
    Chapter3
    Pages173-221
    Number of pages49
    ISBN (Electronic)9781316276273
    ISBN (Print)9781107111752
    DOIs
    Publication statusPublished - 2015

    Bibliographical note

    Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.

    Fingerprint Dive into the research topics of 'Volcanic ash fall hazard and risk'. Together they form a unique fingerprint.

  • Cite this

    Jenkins, S. F., Wilson, T., Magill, C., Miller, V., Stewart, C., Blong, R., ... Costa, A. (2015). Volcanic ash fall hazard and risk. In S. C. Loughlin, S. Sparks, S. K. Brown, S. F. Jenkins, & C. Vye-Brown (Eds.), Global volcanic hazards and risk (pp. 173-221). Cambridge, UK: Cambridge University Press. https://doi.org/10.1017/CBO9781316276273.005