Unmanned aerial vehicle measurements of volcanic carbon dioxide fluxes

We report the first measurements of volcanic gases with an unmanned aerial vehicle (UAV). The data were collected at La Fossa crater, Vulcano, Italy, during April 2007, with a helicopter UAV of 3 kg payload, carrying an ultraviolet spectrometer for remotely sensing the SO(2) flux (8.5 Mg d(-1)), and an infrared spectrometer, and electrochemical sensor assembly for measuring the plume CO(2)/SO(2) ratio; by multiplying these data we compute a CO(2) flux of 170 Mg d(-1). Given the deeper exsolution of carbon dioxide from magma, and its lower solubility in hydro-thermal systems, relative to SO(2), the ability to remotely measure CO(2) fluxes is significant, with promise to provide more profound geochemical insights, and earlier eruption forecasts, than possible with SO(2) fluxes alone: the most ubiquitous current source of remotely sensed volcanic gas data.