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| Titel |
Diffuse CO2 emission from the NE volcanic rift-zone of Tenerife (Canary Islands, Spain): a 15 years geochemical monitoring |
| VerfasserIn |
German Padilla, Mar Alonso, Trevor Shoemaker, Ariane Loisel, Eleazar Padrón, Pedro A. Hernández, 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 |
250128362
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| Publikation (Nr.) |
 EGU/EGU2016-8345.pdf |
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| Zusammenfassung |
| The North East Rift (NER) volcanic zone of Tenerife Island is one of the three volcanic
rift-zones of the island (210 km2). The most recent eruptive activity along the NER volcanic
zone took place in the 1704-1705 period with the volcanic eruptions of Siete Fuentes, Fasnia
and Arafo volcanoes. The aim of this study was to report the results of a soil CO2 efflux
survey undertaken in June 2015, with approximately 580 measuring sites. In-situ
measurements of CO2 efflux from the surface environment of NER volcanic zone were
performed by means of a portable non-dispersive infrared spectrophotometer (NDIR) model
LICOR Li800 following the accumulation chamber method. To quantify the total CO2
emission from NER volcanic zone, soil CO2 efflux contour maps were constructed using
sequential Gaussian simulation (sGs) as interpolation method. The total diffuse CO2 emission
rate was estimated in 1209 t d−1, with CO2 efflux values ranging from non-detectable (∼0.5
g m−2 d−1) up to 123 g m−2 d−1, with an average value of 5.9 g m−2 d−1. If we
compare these results with those obtained in previous surveys developed in a yearly
basis, they reveal slightly variations from 2006 to 2015, with to pulses in the CO2
emission observed in 2007 and 2014. The main temporal variation in the total CO2
output does not seem to be masked by external variations. First peak precedes the
anomalous seismicity registered in and around Tenerife Island between 2009 and
2011, suggesting stress-strain changes at depth as a possible cause for the observed
changes in the total output of diffuse CO2 emission. Second peak could be related
with futures changes in the seismicity. This study demonstrates the importance
of performing soil CO2 efflux surveys as an effective surveillance volcanic tool. |
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