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| Titel |
The 2014 Effusive eruption of Stromboli Volcano: The observed geochemical variations of soil CO2 fluxes and PCO2 in the thermal waters. |
| VerfasserIn |
Salvatore Inguaggiato, Fabio Vita, Agnes Mazot, Marianna Patricia Jacome Paz, Marianna Cangemi, Aldo Sollami |
| 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 |
250130075
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| Publikation (Nr.) |
 EGU/EGU2016-10266.pdf |
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| Zusammenfassung |
| The Stromboli volcano, the more active of the Aeolian Archipelago, is characterized
by an open conduct degassing system with a continuous explosive activity every
20-30’.
In the recent years, effusive activities occurred in 1985, 2002-2003, 2007 and in 2014
while paroxysmal events have taken place only on 5th April 2003 and 15th March
2007.
The geochemical monitoring program has been carried out through routine
thermal well sampling (COA well) and continuous soil CO2 flux measurements on the
summit of the volcano (STR02). The long time series of CO2 fluxes acquired in
1999-2008 period led to the identification of three classes of degassing Low (<
4000 g m−2 d−1), Normal (4000-10,000 g m−2 d−1) and High (> 10,000 g m−2
d−1).
The data of soil CO2 fluxes in the 2010-2012 period showed a sustained degassing with
daily average values almost always higher than the 10,000 g m−2 d−1. During the end
2012-begin 2013 a new trend in increase of soil CO2 flux was recorded with fluxes up to
20,000 g m−2 d−1. It is very interesting to note that the COA well showed an increase of
the dissolved CO2 concentration from 60 to 200 cc/l STP recorded from the end
of the eruption 2007 to mid-2010. Then, after a slight decrease in dissolved CO2
concentration of around 90 cc/l STP (December 2010), there was a new trend in
growth, up to values of about 160 cc/l STP (April 2013). This continuous growth
trend of the partial pressure of CO2 in the thermal aquifer, corroborates abnormal
soil CO2 fluxes recorded at the summit of the volcano, supporting the hypothesis
of a continuous process of pressurization of the volcanic system. On 7 August a
new fracture opened at 650 m a.s.l., and lava moved down along the Sciara del
Fuoco, reaching the sea; concurrently, persistent explosive activity ceased. On 28
October the lava flow abruptly decreased, until 13–17 November, when the effusion
ceased.
Six soil CO2 campaign to estimate the total output discharged from the summit area of
Stromboli was carried out in the period 2007-2015. About 50 point of soil CO2 fluxes
measurements was performed for each survey. These measurements were made on the
summit area, and include the zone of STR02 soil CO2 equipment, covering a surface of about
67500 m2.
In the same period of observation, seven campaigns for the measurement of soil CO2
were also carried out to estimate the total output discharged in a peripheral area of Stromboli
(Scari). The comparison of the data of total diffuse degassing issued in the summit area with
continuous CO2 monitoring carried out at a single point (STR02) showed a good
correlation supporting the hypothesis that the monitored single point is representative
of the overall outgassing volcanic system. The contemporaneous monitoring of
summit soil degassing areas and dissolved CO2 in the aquifers located in the flanks
of the studied volcano give a complete and clear picture of the volcanic activity. |
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