 |
| Titel |
A novel reactor for the simulation of gas and ash interactions in volcanic eruption plumes |
| VerfasserIn |
Paul M. Ayris, Corrado Cimarelli, Pierre Delmelle, Donald B. Dingwell |
| Konferenz |
EGU General Assembly 2014
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250092620
|
| Publikation (Nr.) |
 EGU/EGU2014-6976.pdf |
|
|
|
|
|
| Zusammenfassung |
| The chemical interactions between volcanic ash and the atmosphere, hydrosphere,
pedosphere, cryosphere and biosphere are initially the result of rapid mobilisation of soluble
salts and aqueous acids from wetted particle surfaces. Such surface features are attributable to
the scavenging of sulphur and halide species by ash during its transport through the eruption
plume and volcanic cloud. It has been historically considered (e.g., Rose, 1977) that
the primary mechanism driving scavenging of sulphur and halide species is via
condensation of acid aerosols onto ash surfaces within the cold volcanic cloud.
However, for large explosive eruptions, insights from new experimental highlight
the potential for scavenging via adsorption onto ash within the high-temperature
eruption plume. In previous investigations on simple SO2 (Ayris et al. 2013a) and HCl
systems (Ayris et al. 2013b), we identified ash composition, and the duration and
temperature of gas-ash interaction as key determinants of adsorption-mode scavenging.
However, the first generation of gas-ash reactors could not fully investigate the
interactions between ash and the hydrous volcanic atmosphere; we have therefore
developed an Advanced Gas Ash Reactor (AGAR), which can be fluxed with varying
proportions of H2O, CO2, SO2 and HCl. The AGAR consists of a longitudinally-rotating
quartz glass reaction bulb contained within a horizontal, three-stage tube furnace
operating at temperatures of 25-900°C. A sample mass of up to 100 g can traverse a
thermal gradient via manual repositioning of the reaction bulb within the furnace.
In combination with existing melt synthesis capabilities in our laboratories, this
facility permits a detailed investigation of the effects of ash and gas composition, and
temperature on in-plume scavenging of SO2 and HCl. Additionally, the longitudinal
rotation enables particle-particle interaction under an ‘in-plume’ atmosphere, and
may yield insight into the effects of gas-ash interaction on aggregation processes.
Large quantities of material can be processed in the AGAR. We invite discussions
regarding collaboration with “downstream” projects that would benefit from use of
such materials, or from access to and further development of, the advanced gas-ash
reactor.
References
Ayris, P. M., Lee, A. F., Wilson, K., Kueppers, U., Dingwell, D. B., & Delmelle, P.
(2013a). SO2 sequestration in large volcanic eruptions: high-temperature scavenging by
tephra. Geochimica et Cosmochimica Acta.
Ayris, P. M., Delmelle, P., Maters, E., & Dingwell, D. B. (2013b). Quantifying HCl and
SO2 adsorption by tephra in volcanic eruptions. In EGU General Assembly Conference
Abstracts (Vol. 15, p. 2780).
Rose, W. I. (1977). Scavenging of volcanic aerosol by ash: atmospheric and volcanologic
implications. Geology, 5(10), 621-624. |
|
|
|
|
|
|