Atmospheric dispersion of natural carbon dioxide emissions on Vulcano Island, Italy. Issue 7 (17th July 2014)

• Record Type: Journal Article
• Authors: Granieri, D.; Carapezza, M. L.; Barberi, F.; Ranaldi, M.; Ricci, T.; Tarchini, L.
• Is Part Of: Journal of geophysical research. Volume 119:Issue 7(2014:Jul.)
• Page Start: 5398
• Page End: 5413
• Publication Date: 2014-07-17
• Subjects: Geomagnetism -- Periodicals; Geochemistry -- Periodicals; Geophysics -- Periodicals; Earth sciences -- Periodicals; 551.1
• DOI: 10.1002/2013JB010688
• Languages: English
• ISSNs: 2169-9313

Abstract

<abstract abstract-type="main"> <title>Abstract</title> <p>La Fossa quiescent volcano and its surrounding area on the Island of Vulcano (Italy) are characterized by intensive, persistent degassing through both fumaroles and diffuse soil emissions. Periodic degassing crises occur, with marked increase in temperature and steam and gas output (mostly CO<sub>2</sub>) from crater fumaroles and in CO<sub>2</sub> soil diffuse emission from the crater area as well as from the volcano flanks and base. The gas hazard of the most inhabited part of the island, Vulcano Porto, was investigated by simulating the CO<sub>2</sub> dispersion in the atmosphere under different wind conditions. The DISGAS (DISpersion of GAS) code, an Eulerian model based on advection‐diffusion equations, was used together with the mass‐consistent Diagnostic Wind Model. Numerical simulations were validated by measurements of air CO<sub>2</sub> concentration inside the village and along the crater's rim by means of a Soil CO<sub>2</sub> Automatic Station and a Tunable Diode Laser device. The results show that in the village of Vulcano Porto, the CO<sub>2</sub> air concentration is mostly due to local soil degassing, while the contribution from the crater gas emission is negligible at the breathing height for humans and always remains well below the lowest indoor CO<sub>2</sub> concentration threshold recommended by the health authorities (1000 ppm). Outdoor excess CO<sub>2</sub> maxima up to 200 ppm above local background CO<sub>2</sub> air concentration are estimated in the center of the village and up to 100 ppm in other zones. However, in some ground excavations or in basements the health code threshold can be exceeded. In the crater area, because of the combined effect of fumaroles and diffuse soil emissions, CO<sub>2</sub> air concentrations can reach 5000–7000 ppm in low‐wind conditions and pose a health hazard for visitors.</p> </abstract>