UV camera measurement at a dormant volcano

The UV camera is now becoming a new important tool in the armory of volcano geochemists for high rate SO2 flux measurements. The high spatial resolution of the camera is particularly useful for exploring multiple-source SO2 gas emissions, as the large composite fumarolic systems topping most quiescent volcanoes. We report here on the first SO2 flux measurements from individual fumaroles of the fumarolic field of La Fossa crater (Vulcano island, Aeolian island), which we performed using a UV camera in two field campaigns on November 12, 2009 and February 4, 2010. Making advantage of the high temporal and spatial resolution of the UV camera, we derived ~0.5 Hz SO2 flux time-series for the main fumarolic areas, deriving fluxes from individual fumaroles ranging from 1.4 to 5.2 tons/day; and a total cumulative flux from the whole system of ~ 13 tons/day. The data of each campaign were implemented by determining, for each fumarolic vent, the molar SO2/H2S and CO2/SO2 ratios (which we derived using a portable multi-gas analyzer). Using the SO2 flux data in tandem with the molar ratios, we also calculated the flux of volcanic species CO2 (355 tons/day) and H2S (5.6 tons/day) from Vulcano island.