Volcanic emissions are a critical pathway in Earth’s carbon cycle. Here, we show that aerial measurements of volcanic gases using unoccupied aerial systems (UAS) transform our ability to measure and monitor plumes remotely and to constrain global volatile fluxes from volcanoes. Combining multi-scale measurements from ground-based remote sensing, long-range aerial sampling, and satellites, we present comprehensive gas fluxes—3760 ± [600, 310] tons day⁻¹ CO₂ and 5150 ± [730, 340] tons day⁻¹ SO₂—for a strong yet previously uncharacterized volcanic emitter: Manam, Papua New Guinea. The CO₂/S_T ratio of 1.07 ± 0.06 suggests a modest slab sediment contribution to the sub-arc mantle. We find that aerial strategies reduce uncertainties associated with ground-based remote sensing of SO₂ flux and enable near–real-time measurements of plume chemistry and carbon isotope composition. Our data emphasize the need to account for time averaging of temporal variability in volcanic gas emissions in global flux estimates.

Volcán de Fuego (Guatemala) is capable of large (VEI?2) explosive eruptions like that of June 2018, which triggered pyroclastic flows that devastated the community of San Miguel Los Lotes, causing hundreds of fatalities and severe long-term socio-economic impacts. Future volcanic risk mitigation efforts are likely to involve temporary evacuation of local communities, the success of which requires co-operation between locals, scientists, and decision-makers. However, how locals' experiences of eruptive activity influence their responses to evacuation has not been studied in detail. We investigated these themes through semi-structured interviews that focussed on direct experience as opposed to volcanic risk perception, revealing substantial differences between scientists' and locals' observations of Fuego’s activity. Furthermore, a disparity emerged between communities on Fuego's west and east flanks in terms of direct prior eruption experience and communication with authorities. These findings have serious implications for future evacuation efforts at Fuego and at other highly populated volcanoes.

A team from the University of Bristol have developed a method of operating fixed wing Unmanned Aerial Vehicles (UAVs) at long-range and high-altitude over Volcán de Fuego in Guatemala for the purposes of volcanic monitoring and ash-sampling. Conventionally, the mission plans must be carefully designed prior to flight, to cope with altitude gains in excess of 3000 m, reaching 9 km from the ground control station and 4500 m above mean sea level. This means the climb route cannot be modified mid-flight. At these scales, atmospheric conditions change over the course of a flight and so a real-time trajectory planner (RTTP) is desirable, calculating a route on-board the aircraft. This paper presents an RTTP based around a genetic algorithm optimisation running on a Raspberry Pi 3 B+, the first of its kind to be flown on-board a UAV. Four flights are presented, each having calculated a new and valid trajectory on-board, from the ground control station to the summit region of Volcań de Fuego. The RTTP flights are shown to have approximately equivalent efficiency characteristics to conventionally planned missions. This technology is promising for the future of long-range UAV operations and further development is likely to see significant energy and efficiency savings.