 |
| Titel |
Characterisation of the magmatic signature in gas emissions from Turrialba Volcano, Costa Rica |
| VerfasserIn |
Y. Moussallam, N. Peters, C. Ramírez, C. Oppenheimer  , A. Aiuppa, G. Giudice |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1869-9510
|
| Digitales Dokument |
URL |
| Erschienen |
In: Solid Earth ; 5, no. 2 ; Nr. 5, no. 2 (2014-12-20), S.1341-1350 |
| Datensatznummer |
250115361
|
| Publikation (Nr.) |
 copernicus.org/se-5-1341-2014.pdf |
|
|
|
|
|
| Zusammenfassung |
| The equilibrium composition of volcanic gases with their magma is often
overprinted by interaction with a shallow hydrothermal system. Identifying
the magmatic signature of volcanic gases is critical to relate their
composition to properties of the magma (temperature, fO2, gas-melt
segregation depth). We report measurements of the chemical composition and
flux of the major gas species emitted from Turrialba Volcano during March
2013. Measurements were made of two vents in the summit region, one of which
opened in 2010 and the other in 2012. We determined an average SO2
flux of 5.2 ± 1.9 kg s-1 using scanning ultraviolet
spectroscopy, and molar proportions of H2O, CO2, SO2,
HCl, CO and H2 gases of 94.16, 4.03, 1.56, 0.23, 0.003 and
0.009% respectively by open-path Fourier transform infrared (FTIR)
spectrometry and a multi-species gas-sensing system. Together, these data
imply fluxes of 88, 8, 0.44, 5 × 10-3 and 1 × 10-3 kg s-1 for H2O, CO2, HCl, CO and
H2 respectively. Although H2S was detected, its concentration
could not be resolved. HF was not detected. The chemical signature of the gas
from both vents was found to be broadly similar. Following the opening of the
2010 and 2012 vents we found limited to negligible interaction of the
magmatic gas with the hydrothermal system has occurred and the gas
composition of the volcanic plume is broadly representative of equilibrium
with the magma. The time evolution of the gas composition, the continuous
emission of large quantities of SO2, and the physical evolution of
the summit area with new vent openings and more frequent eruptions all point
towards a continuous drying of the hydrothermal system at Turrialba's summit
at an apparently increasing rate. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|