The expedition
The South American Andes hold nearly 200 active volcanoes, but their remoteness, their height — up to 6,893 m — and the absence of trails to most summits had left the whole arc almost blank in the global database of volcanic gas emissions. Trail by Fire set out to correct that in a single campaign: to take a snapshot of what the volcanoes of the Nazca subduction zone release, and so to answer how efficiently subduction recycles water and carbon dioxide back to the surface. The team was six young volcanologists — Dr Yves Moussallam of the Scripps Institution of Oceanography, who led it, Dr Nial Peters of the University of Cambridge, Dr Aaron Curtis of New Mexico Tech, Dr Ian Schipper of Victoria University of Wellington, Dr Talfan Barnie of the Open University and Dr Philipson Bani of the Institut de Recherche pour le Développement. They won the 2015 Land Rover Bursary, administered by the Royal Geographical Society (with IBG), which brought £30,000 and the loan of a Defender 110 — the white left-hand-drive 110 XS station wagon VU14 XUG that the Grand Alpine Tour had used in the Alps the summer before.
Land Rover's Special Vehicle Operations at its Oxford Road facility built the car with the scientists into what they called the world's first all-terrain mobile volcano observatory. It carried an extra-large independent battery system to run the instruments in the deep field, an aircraft-grade anti-vibration housing for a Delta Ray isotope-ratio infrared spectrometer, compressed reference gases, a fridge, a synthetic-rope winch, LED lighting and a large side-deployable tent that served as living quarters and office; it was fitted with spectrometers so that the vehicle itself could traverse volcanic plumes. The expedition was launched in October 2015 and the car was shipped to Chile, where the team readied it and sourced local parts at Iquique in early November.
From Arica the Defender climbed to 5,300 m at Guallatiri on the Bolivian border in late November — above its design ceiling of 4,500 m — for remote SO2 flux measurements of the 6,100 m volcano. Getting into Peru cost six hours at the border and the help of diplomats. In southern Peru, working with the Observatorio Vulcanológico del INGEMMET and with colleagues from the University of Palermo and INGV who joined for that leg, the team climbed Ubinas and Sabancaya, both near 6,000 m; the first full gas composition and flux measurements at Sabancaya showed intense, periodic degassing, and the two volcanoes turned out to release two-thirds of all the gas from the central section of the arc. Fumaroles on the lower slopes of Hualca Hualca near Chivay filled a rest day; El Misti above Arequipa, climbed on 1 December, surprised them with vents at nearly 300°C emitting magmatic rather than hydrothermal gas; Ticsani, Tutupaca and Yucamane were the 'three lightly sleeping giants' of the south.
Back in Chile the Trail ran down the altiplano: Tacora, the northernmost Chilean volcano with its old sulphur mines and railway; Isluga, where the gas-sampling quadcopter flew on Christmas Day; Lascar, climbed four times, with what the team claimed as the highest quadcopter flight and the longest improvised gas-collecting pole; and Lastarria, the last volcano of the Central Volcanic Zone before the 600 km Pampean Gap, where the arc goes quiet. In the Southern Volcanic Zone, working with OVDAS, they were belayed down the newly formed eruptive vent at Nevados de Chillán and ended at Villarrica, whose lava lake they watched through storms and ice for a month, timing their ground measurements with acquisitions by NASA's EO-1 and Terra satellites. Three types of UAV flew instruments through the plumes.
All 15 target volcanoes were visited, nearly a terabit of data was collected and, after 17,000 km, the four-month campaign closed in February 2016. Papers followed on the Peruvian arc, on El Misti's permeable conduit and on Villarrica's steady degassing; isotopes showed most of the CO2 came from the subducting slab. The team returned in 2017 for Ecuador — Tungurahua, Cotopaxi, Reventador and Guagua Pichincha — bringing the total to more than 20,000 km and more than 20 volcanoes. The car was recorded as exported after its last British MOT in November 2019.
_(30031766090).jpg){kind=link}
.jpg){kind=link}
.jpg){kind=link}