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| Titel |
Monitoring Cumbre Vieja volcano (La Palma, Canary Islands) from 2001 to 2015
by means of diffuse CO2 degassing |
| VerfasserIn |
Eleazar Padrón, Hannah Berry, Helen Robinson, Fátima Rodriguez, Samara Dionis, Nemesio M. Pérez |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250128289
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| Publikation (Nr.) |
 EGU/EGU2016-8269.pdf |
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| Zusammenfassung |
| La Palma Island, the fifth longest (706 km2) and second highest (2,423 m asl) of the
Canary Islands, is located at the northwestern end of the archipelago. Subaerial
volcanic activity on La Palma started ∼2.0 My ago and has taken place exclusively at
the southern part of the island in the last 123 ka, where Cumbre Vieja volcano,
the most active basaltic volcano in the Canaries, has been constructed. Cumbre
Vieja volcano, which has been likened to a Hawaiian-style rift zone, includes a
main north-south rift zone 20 km long and up to 1,950 m in elevation, and covers
220 km2 with vents located also at the northwest and northeast. Nowadays, there
are no visible gas emissions from fumaroles or hot springs at Cumbre Vieja, but
large amounts of CO2 are released as diffuse soil emanations from the flanks of the
volcano. Recent studies have shown that enhanced endogenous contributions of
deep-seated CO2 might have been responsible for higher diffuse CO2 emission values
(Padrón et al., 2015). We report here the latest results of the diffuse CO2 efflux
survey at Cumbre Vieja volcano. The CO2 efflux measurements were taken using the
accumulation chamber method in the summer period of 2015 to constrain the total CO2
output from the studied area and to evaluate occasional CO2 efflux surveys as a
volcanic surveillance tool for Cumbre Vieja. Soil CO2 efflux values ranged from
non-detectable up to 360 g m−2 d−1. Spatial distribution maps were constructed following
the sequential Gaussian simulation (sGs) procedure. The spatial distribution of
diffuse CO2 emission values did not seem to be controlled by the main structural
features of the volcano since the highest values were measured in the southern
part. The total CO2 output released to the atmosphere in a diffuse way has been
estimated at 359 t d−1, which represents one of the lowest emission rates reported
since 1997 (Padrón et al., 2015). Our results confirm the volcanic quiescence state
of Cumbre Vieja, but reassert the need for periodic diffuse emission surveys as a
powerful volcanic surveillance tool in volcanoes where visible gas emanations are
absent.
References:
Padrón et al., 2015. Bull. Volcanol. 77, 28. |
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