Trail by Fire


From October 2015 to February 2016, an international team of six early career volcanologists spent five months in South America investigating volcanic gas emissions along the length of the Nazca plate subduction zone. Their research during the “Trail by Fire Expedition” is helping quantify volcanic gas emissions and volcanoes’ role in cycling volatile through Earth’s mantle and crust. 

The team traversed more than 17,000 kilometers from Peru to the southern tip of Chile, climbing 15 active volcanoes, reaching altitudes over 6000 m. This research aligned with the Deep Carbon Observatory’s DECADE initiative, which was developed to clarify quantities and movements of volcanic carbon emissions on a global scale. In February 2017, the team headed back to South America to add to their data by investigating Ecuador’s spectacular and highly active volcanoes. Trail by Fire was primarily funded by the 2015 Land Rover Bursary, administered by the Royal Geographical Society (with the Institute of British Geographers) and received additional support from the DCO, Thermo Fisher scientific, Turbo Ace, Ocean Optics, Crowcon, Air Liquide, Team Black Sheep and Cactus Outdoor. 

TBF map
Outlined map of South America showing the location of active volcanoes in relation to the Nazca subduction zone. Volcanoes targeted by the expedition are shown in red. Credit: Yves Moussallam

To conduct this research, the team assembled a suite of cutting edge scientific instruments housed in the world’s first Mobile Volcano Observatory: a specially modified Land Rover Defender 110. This custom-made vehicle, prepared by Land Rover Special Vehicle Operation together with the scientific team, allowed the team to access remote volcanoes, never studied before. 

To measure the gas composition the team made direct measurements in volcanic plumes. Using remote sensing methods simultaneously to measure the flux of sulfur dioxide and combining both sets of measurements allowed them to estimate the total volatile flux at each volcano. Besides measuring the flux and composition of the gases emitted by volcanoes along way, the team was also interested in determining the origin of these volatiles. To do so they used a Delta Ray Isotope Ratio Infrared Spectrometer to measure the isotopic composition of the volcanic carbon emitted. Another novel approach of the Trail by Fire was in the intensive use of unnamed aerial vehicles (UAV). Three types of UAV were flown during the expedition, each fitted with a different scientific instrument. The first UAV was fitted with an Ocean Optic Flame spectrometer to perform air-born traverses underneath volcanic plumes, measuring SO2. The second setup was flying a miniature version of the “Multi-Gas” measuring the ratio of CO2 to SO2 species in the plume. The last setup was capturing direct samples of the plume brought back for further analysis at the mobile observatory.  

In collaboration with partners at JPL and NASA, satellite acquisitions were timed near-simultaneously with field visits. These observations will be used to extrapolate the team’s point observations in space and time and put them in the context of changes in activity over the past decade. Currently, the team is processing the back catalogue of satellite data to build time series of activity at all the volcanoes we visited, to compare with field observations.

Along the Trail, the team worked closely with local observatories; the Observatorio Vulcanológico del INGEMMET (OVI) in Perou, the Observatorio Volcanológico de Los Andes del Sur (OVDAS) in Chile and the Instituto Geofisico de la Escuela Politecnica Nacional (IG-EPN) in Ecuador. In addition, colleagues from the University of Palermo and INGV Palermo joined the team for part of the Peruvian and Ecuadorian legs of the expedition. The involvement of these partners and friends, together with the scientist’s home institutes and many sponsors made this expedition possible. 

TBF on Villarica


Research Team


Yves Moussallam

Expedition Website 


Taking the Pulse of Andean Volcanoes

It has been nearly two years since the Trail by Fire crew started preparing for their expedition along the South American Andes, which took place from October 2015 to February 2016 and for an additional month in February to March 2017. The team have published an initial suite of four papers. In this article, Yves Moussallam (recipient of the 2016 DCO Emerging Leader Award) summarizes the team’s findings to date.

Read more. 

Blog: Trail By Fire Part 2

Read regular updates from the team as they explored volcanoes in Ecuador.

Blog: Trail By Fire Part 1

Read regular updates from the team over the course of their first six months on the Trail by Fire. 

Further Reading

Moussallam, Y., Bani, P., Curtis, A., Barnie, T., Moussallam, M., Peters, N., Schipper, C.I., Aiuppa, A., Giudice, G., Amigo, Á., Velasquez, G., Cardona, C., 2016. Sustaining persistent lava lakes: Observations from high-resolution gas measurements at Villarrica volcano, Chile.Earth and Planetary Science Letters 454, 237–247. doi:10.1016/j.epsl.2016.09.012

Moussallam, Y., Peters, N., Masias, P., Apaza, F., Barnie, T., Schipper, C.I., Curtis, A., Tamburello, G., Aiuppa, A., Bani, P., Giudice, G., Pieri, D., Davies, A.G., Oppenheimer, C., 2017a. Magmatic gas percolation through the old lava dome of El Misti volcano. Bull Volcanol 79, 46. doi:10.1007/s00445-017-1129-5

Moussallam, Y., Tamburello, G., Peters, N., Apaza, F., Schipper, C.I., Curtis, A., Aiuppa, A., Masias, P., Boichu, M., Bauduin, S., Barnie, T., Bani, P., Giudice, G., Moussallam, M., 2017b. Volcanic gas emissions and degassing dynamics at Ubinas and Sabancaya volcanoes; implications for the volatile budget of the central volcanic zone. Journal of Volcanology and Geothermal Research. doi:10.1016/j.jvolgeores.2017.06.027

Schipper, C.I., Moussallam, Y., Curtis, A., Peters, N., Barnie, T., Bani, P., Jost, H.J., Hamilton, D., Aiuppa, A., Tamburello, G., Giudice, G., 2017. Isotopically (δ13C and δ18O) heavy volcanic plumes from Central Andean volcanoes: a field study. Bull Volcanol 79, 65. doi:10.1007/s00445-017-1146-4

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