Publication Date:
2017-04-04
Description:
Several sites with anomalous emissions of carbon dioxide were investigated in the region south of Mt. Etna volcano in order to
assess the types of emission (focused and/or diffuse), their surface extension and the total output of CO2. Most of the studied
emissions are located on the southwest boundary of Mt. Etna, near the town of Paternò. They consist of three mud volcanoes
(known as Salinelle), one spring with bubbling gas (Acqua Grassa) and one area of diffuse degassing (Peschería). Another site
(Naftía Lake) with remarkable gas emissions (bubbling gas into a lake as well as adjacent areas of diffuse soil degassing) is located
further southwest of Mt. Etna in an area of extinct Quaternary volcanism on the northwest margin of Hyblean Mts. In all of these
areas the origin of the highest CO2 emissions is clearly magmatic, and degassing to the atmosphere occurs mostly through tectonic
structures, probably at a regional scale. The magmatic source that feeds anomalous degassing in the above areas is likely to be the
same that feeds volcanic activity at Mt. Etna.
Focused degassing was measured at each emission vent using devices that measure the air speed, whereas diffuse soil degassing
was measured using the accumulation chamber method. In total, 712 measurements were carried out (146 in focused degassing
vents, 566 on diffuse degassing areas). Single CO2 output values ranged from 1.8 10−5 to 1.68 kg s−1. In the case of diffuse
degassing areas, statistical analyses allowed to discriminate between biogenic CO2 and CO2 deriving from a magmatichydrothermal
source. Only the efflux values from the latter source were considered in the output estimates. The total estimated
output thus obtained was about 2.61 kg s−1, relevant to a total surface of about 146,500 m2 (which includes only the magmatic CO2
emissions). This value is comparable with that of most non-volcanic emissions from geothermal and/or faulted areas of centralsouthern
Italy, as well with the CO2 output from some of the volcanic areas of Italy.
Description:
Istituto Nazionale
di Geofisica e Vulcanologia; Dipartimento per
la Protezione Civile.
Description:
Published
Description:
46–63
Description:
4.5. Degassamento naturale
Description:
JCR Journal
Description:
reserved
Keywords:
Mt. Etna
;
mud volcanoes
;
soil CO2 effluxes
;
magmatic degassing
;
04. Solid Earth::04.08. Volcanology::04.08.01. Gases
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
