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| Titel |
First volcanic CO2 budget estimate for three actively degassing volcanoes in the Central American Volcanic Arc |
| VerfasserIn |
Philippe Robidoux, Alessandro Aiuppa, Vladimir Conde, Bo Galle, Gaetano Giudice, Geoffroy Avard, Angélica Muñoz |
| 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 |
250087432
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| Publikation (Nr.) |
 EGU/EGU2014-1480.pdf |
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| Zusammenfassung |
| CO2 is a key chemical tracer for exploring volcanic degassing mechanisms of basaltic
magmatic systems (1). The rate of CO2 release from sub-aerial volcanism is monitored via
studies on volcanic plumes and fumaroles, but information is still sparse and incomplete for
many regions of the globe, including the majority of the volcanoes in the Central American
Volcanic Arc (2). Here, we use a combination of remote sensing techniques and in-situ
measurements of volcanic gas plumes to provide a first estimate of the CO2 output from three
degassing volcanoes in Central America: Turrialba, in Costa Rica, and Telica and San
Cristobal, in Nicaragua. During a field campaign in March-April 2013, we obtained (for the
three volcanoes) a simultaneous record of SO2 fluxes (from the NOVAC network (3)) and
CO2 vs. SO2 concentrations in the near-vent plumes (obtained via a temporary installed
fully-automated Multi-GAS instrument (4)). The Multi-GAS time-series allowed to calculate
the plume CO2/SO2 ratios for different intervals of time, showing relatively stable gas
compositions. Distinct CO2 - SO2 - H2O proportions were observed at the three volcanoes,
but still within the range of volcanic arc gas (5). The CO2/SO2 ratios were then
multiplied by the SO2 flux in order to derive the CO2 output. At Turrialba, CO2/SO2
ratios fluctuated, between March 12 and 19, between 1.1 and 5.7, and the CO2flux
was evaluated at ~1000-1350 t/d (6). At Telica, between March 23 and April 8,
a somewhat higher CO2/SO2 ratio was observed (3.3 ± 1.0), although the CO2
flux was evaluated at only ~100-500 t/d (6). At San Cristobal, where observations
were taken between April 11 and 15, the CO2/SO2 ratio ranged between 1.8 and
7.4, with a mean CO2 flux of 753 t/d. These measurements contribute refining the
current estimates of the total CO2 output from the Central American Volcanic Arc
(7).
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Conde, V. et al. (2013). International Journal of Earth Sciences, (submitted)
Mather et al (2006). J. Volcanol. Geotherm. Res., 149, 297-311 |
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