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| Titel |
The source and longevity of sulfur in an Icelandic flood basalt eruption plume |
| VerfasserIn |
Evgenia Ilyinskaya, Marie Edmonds, Tamsin Mather, Anja Schmidt, Margaret Hartley, Clive Oppenheimer  , Francis Pope, Amy Donovan, Olgeir Sigmarsson, John Maclennan, Oliver Shorttle, Peter Francis , Baldur Bergsson, Sara Barsotti, Thorvaldur Thordarson , Enikö Bali, Nicole Keller, Andri Stefansson |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250110273
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| Publikation (Nr.) |
 EGU/EGU2015-10253.pdf |
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| Zusammenfassung |
| The Holuhraun fissure eruption (Bárðarbunga volcanic system, central Iceland) has been
ongoing since 31 August 2014 and is now the largest in Europe since the 1783-84 Laki event.
For the first time in the modern age we have the opportunity to study at first hand the
environmental impact of a flood basalt fissure eruption (>1 km3 lava). Flood basalt eruptions
are one of the most hazardous volcanic scenarios in Iceland and have had enormous societal
and economic consequences across the northern hemisphere in the past. The Laki
eruption caused the deaths of >20% of the Icelandic population by environmental
pollution and famine and potentially also increased European levels of mortality
through air pollution by sulphur-bearing gas and aerosol. A flood basalt eruption was
included in the UK National Risk Register in 2012 as one of the highest priority
risks.
The gas emissions from Holuhraun have been sustained since its beginning, repeatedly
causing severe air pollution in populated areas in Iceland. During 18-22 September, SO2
fluxes reached 45 kt/day, a rate of outgassing rarely observed during sustained eruptions,
suggesting that the sulfur loading per kg of erupted magma exceeds both that of other recent
eruptions in Iceland and perhaps also other historic basaltic eruptions globally. This raises
key questions regarding the origin of these prodigious quantities of sulphur. A lack of
understanding of the source of this sulfur, the conversion rates of SO2 gas into aerosol, the
residence times of aerosol in the plume and the dependence of these on meteorological
factors is limiting our confidence in the ability of atmospheric models to forecast gas
and aerosol concentrations in the near- and far-field from Icelandic flood basalt
eruptions.
In 2015 our group is undertaking a project funded by UK NERC urgency scheme to
investigate several aspects of the sulfur budget at Holuhraun using a novel and powerful
approach involving simultaneous tracking of sulfur and chalcophile metals through
the melt and the volcanic plume. By combining petrological analysis, in-plume
sampling of gases and aerosol, and plume dispersion modelling, we will address two
principal research objectives related to understanding the sulfur systematics of the
eruption: (1) To examine the sulfur budget as recorded in the erupted rocks in the form
of dissolved sulfur and sulfide minerals, which break down on eruption and (2)
To investigate the SO2 lifetime in the atmosphere, by measurements in the both
young and ageing eruption plume and plume dispersion modelling In addition we
will analyse the characteristics of the aerosol mass necessary for health impact
assessment.
We will carry out two field campaigns, in January 2015 (short daylight) and, if the
eruption is still ongoing, in April 2015 (long daylight). Here we present the first results of our
project following the winter campaign. |
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