Unmanned aerial vehicles (UAVs) carrying lightweight sensors were used to collect temperature, humidity and thermal data within the remote volcanic clouds of Guatemala. The UAVs also took images of multiple volcanic eruptions in real time. The research team believes this to be one of the first times that fixed-wing UAVs have been used at a site such as Volcán de Fuego, where the lack of close access to the summit vent has prevented robust gas measurements in the past. The UAVs were successfully flown beyond visual line of sight at distances of up to eight kilometers and at 10,000 feet above the launch site. Volcán de Fuego (near with plume), neighboring Volcán de Acatenango and Volcán de Agua (far). Picture taken on a beyond-visual-line-of-sight long-range flight. Courtesy of Universities of Bristol, Cambridge and INSIVUMEH. The research team, from the University of Bristol and University of Cambridge, also used the drones to map the topology of a barranca and the volcanic deposits within it. The data they captured will assist in modeling volcanic flow pathways and in determining the potential impact of future eruptions on nearby settlements. Researcher Kieran Wood from the University of Bristol said, “… multiple imaging flights over several days captured the rapidly changing topography of Fuego's summit. These showed that the volcano was erupting from not just one, but two active summit vents.” The summit of Volcán de Fuego showing an active vent. Courtesy of Universities of Bristol, Cambridge and INSIVUMEH. The team plans to return to Guatemala with a wider range of sensors including a multiGAS gas analyser (CO2, SO2, H2S); a four-stage filter pack; carbon stubs for ash sampling; thermal and visual cameras; and atmospheric sensors. Emma Liu, volcanologist from the University of Cambridge, said, “Drones offer an invaluable solution to the challenges of in-situ sampling and routine monitoring of volcanic emissions, particularly those where the near-vent region is prohibitively hazardous or inaccessible. These sensors not only help to understand emissions from volcanoes, they could also be used in the future to help alert local communities of impending eruptions — particularly if the flights can be automated.” The flight team (left to right): Colin Greatwood, Thomas Richardson, Ben Schellenberg, Emma Liu and Kieran Wood. Courtesy of Universities of Bristol and Cambridge.