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| Titel |
High temperature SO2 adsorption by volcanic glasses: New implications for gas scavenging processes in the eruption plume |
| VerfasserIn |
Paul M. Ayris, Pierre Delmelle, Adam F. Lee, Karen Wilson, Donald B. Dingwell, Ulrich Kueppers |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250032293
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| Zusammenfassung |
| The impacts of volcanic ash in the environment may be modified by gas scavenging processes
by ash surfaces within the volcanic eruption plume. Current understanding of the potential
environmental impacts associated with in-plume modifications to ash surface chemical
properties, i.e. through the emplacement of soluble surface salts, is impeded by a limited
understanding of the mechanisms controlling gas scavenging within the plume. During SO2
adsorption experiments on volcanic glasses at 25-800Ë C, crystalline CaSO4 was
found to be the sole reaction product at >500Ë C. CaSO4 was hypothesised to be
formed by segregation from the glass surface driven by Ca diffusion from the glass
interior. This study has illustrated that gas scavenging reactions are not simply a
product of gas adsorption and acid condensation on solid ash particle surfaces, but
may be controlled by more complex processes acting on molten ash surfaces in the
high temperature eruption plume. It may be possible that these high temperature
processes may extend into the subsurface volcanic or magmatic environments. Surface
modification at high temperature may dictate the extent of gas scavenging and the
formation of any associated reaction products upon ash surfaces, and so may influence
the extent of any potential environmental impacts occurring after ash emission. |
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