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| Titel |
Catalogue of the main gas manifestation of Greece: Geochemical characterisation and preliminary gas hazard assessment |
| VerfasserIn |
Walter D'Alessandro, Konstantinos Kyriakopoulos, Sergio Calabrese |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250088053
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| Publikation (Nr.) |
 EGU/EGU2014-2127.pdf |
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| Zusammenfassung |
| Like other geodynamically active areas, the Hellenic territory is also affected by a large
number of geogenic gas manifestations. These occur either in form of point sources
(fumaroles, mofettes, bubbling gases) or as diffuse soil gas emanations.
The present work produced a first catalogue of the geogenic gas manifestations of the whole
Hellenic territory also considering a few literature data. All collected samples were analysed
for their chemical composition (He, Ne, Ar, O2, N2, H2, H2S, CO, CH4 and CO2) and
isotopic composition (He, CO2-C, CH4-C, N2-N).
Geogenic sources release huge amounts of gases, which, apart from having important
influences on the global climate, could have strong impact on human health. Gases have both
acute and chronic effects. Carbon Dioxide and Hydrogen Sulphide are the main gases
responsible for acute mortality due to their asphyxiating and/or toxic properties. Methane
instead represents a risk for its explosive properties.
Gas hazard is often disregarded because in fatal episodes connected to geogenic gases the
death cause is often not correctly attributed. Due to the fact that geodynamic active areas can
release geogenic gases for million years over wide areas, it is important not to underestimate
potential risks.
A preliminary estimation of the gas hazard has been made for the time period of the last 20
years considering the whole population of Greece. In this period at least two fatal episodes
with a total of three victims could be certainly attributed to geogenic gases (specifically
CO2). This would give a risk of 1.3x10-8 fatality from geogenic gas manifestations per
annum. Such value, although probably underestimated, is much lower than most other natural
or anthropogenic risks. Nevertheless this risk, being unevenly distributed along the whole
territory, should not be overlooked especially in areas with high density of gas manifestations
and high soil gas fluxes. |
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