Continous Monitoring of Diffuse Soil Degassing on mt. Etna (Italy)
Abstract
Mt. Etna is an active volcano located in the Southern region of Italy, its last eruption was in July 2001. Periodical surveys on this volcano were carried out since 1989 in order to measure diffuse CO2 flux from soil. The acquired data suggest a strong dependance of peripheral soil gas emissions from volcanic activity. In particular, rapid decreases of diffuse emissions were observed before the onset of the eruption 1989 and 1991-1993 and very low values were also observed during all the eruptive phases. These data were interpreted as an increase of the gas drainage capability of the eruptive vents to the detriment of the peripheral areas (Giammanco et al.1995). According to these observations a soil gas network was designed in order to acquire more information on volcanic activity. The whole project consists of 15 remote stations located on the South and East side of the volcanic edifice where periodical surveys highlighted the highest values of diffuse soil gas emissions. Each remote stations of the gas network is able to measure CO2 and CH4 fluxes from soil according to the method proposed by Gurrieri and Valenza (1988). Moreover, the stations are also equipped with several sensors to measure soil water content (which gives indirect information of soil permeability variations with rainfall) and the atmospheric parameters: pressure, temperature, relative air water content, rainfall, wind speed and wind direction. A very low correlation has been found between soil degassing and atmospheric parameters in areas characterised by strong soil gas emissions. This seems to be due to the volcanic trend at the measuring time, which totally overlapped the flux variations induced by atmospheric variations.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2002
- Bibcode:
- 2002AGUFM.V21A1183G
- Keywords:
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- 4820 Gases;
- 4825 Geochemistry;
- 4894 Instruments and techniques