The Trail By Fire: 6 Scientists. 15 Volcanoes. 1 Pair of Supertrousers (each!)

The Trail By Fire: 6 Scientists. 15 Volcanoes. 1 Pair of Supertrousers (each!)

The Trail By Fire: 6 Scientists. 15 Volcanoes. 1 Pair of Supertrousers (each!)

In November 2015, a team of early-career volcanologists set out to measure the gases emitted from as many volcanoes as possible along the Nazca Subduction Zone of South America. This “Trail By Fire” was a scientific undertaking of unprecedented scale – and the team hadn’t a THING to wear!

Subduction zones occur where two tectonic plates collide, and one of them sinks beneath the other. Off the west coast of South America, the Pacific oceanic plate subducts beneath the South American continental plate to form the Nazca Subduction Zone. The subducting plate gets heated, dehydrated, and melted to form magma, which then erupts from the 200+ volcanoes that form a chain stretching from Columbia to Southern Chile. Subduction zones act as a recycling plant for many elements, including “volatiles” such as CO2, water and sulfur, which are important components of Earth’s atmosphere. The efficiency of volatile recycling is poorly known – we can guess the quantity of volatiles that are subducted, but it is difficult to measure the amount that are then released to the atmosphere through active volcanoes. It was the team’s mission to measure gases at as many volcanoes as possible along the Nazca Subduction Zone, to answer this fundamental scientific question.

Volcanology is a wild endeavour. It combines elements of tramping and mountaineering, but with packs full of high-tech gear, into areas ripe with acidic water, noxious fumes, and other hazards. What DOES one wear when having to travel light and hard, at high elevation, and in adverse and changing conditions that bridge the natural and industrial?

Ian Schipper (Victoria University of Wellington) was the only NZ-based member of the crew, and the only one with previous knowledge of Cactus’ flagship trousers. When he turned up with one pair for each member of the team, the fearless leader Yves Moussallam (France/USA), zealously unwrapped his Supertrousers, only to exclaim: “How are we supposed to walk in these things?”

The crew started in Northern Chile, pushing their Land Rover mobile volcano observatory to new heights on active volcanoes such as the 6071-metre Guallatiri, and deep into the volcanic wilds of Peru. A dynamic summit attack on the snow- and sulfur- encrusted, 5822-metre El Misti Volcano led Nial Peters (UK), a veteran of active volcanoes in Antarctica, to recall: “That was the hardest thing I’ve ever done… I couldn’t have made it without my Supertrousers.”

A backbreaking tour of the sulfur-rich volcanoes of Southern Peru included a stop at Ticsani volcano. The crew got (too) deep into direct sampling of some hot, highly acidic fumaroles. Inadvertently standing on a patch of diffuse degassing, Ian had the sole burned off one boot. Similarly, the (inappropriately dressed) Aaron Curtis (USA) rose from his nearby seat to find a cool breeze blowing… the acid and heat had burned a hole through the bottom of his lesser trousers. He cried: “I should have had my Supertrousers on!”

The expedition went from volcano to volcano, but naturally had to call in at some of the great South American cities, to liaise with local experts. In Peru, the team worked closely with researchers from OVDAS, and in Chile with those from SERNAGEOMIN. Team member Talfan Barnie (UK) worried: “What should we wear to the official meeting with the government representatives?” but he was quickly consoled by Philipson Bani (France/Vanuatu): “Mate, just dust off your Supertrousers!”

Overall, the team travelled over 17,000 km, visited 15 volcanoes, and used high-tech remote sensing gear, direct sampling gear, and satellite support, to obtain an unprecedented data set of gas flux measurements and samples from the Nazca Subduction Zone.

Work on active volcanoes is difficult, but the rewards go beyond the scientific or professional. Fieldwork such as on the Trail By Fire allows one to feel the very heart of the Earth beating. It tests the limits of one’s stamina, clarity, sense of place in the universe, and gear. Four months after unwrapping their trousers, weary from the road, the elevation, the ash and the fumes, the crew was called upon to undertake a special task. They were asked to approach and sample the vent of Volcan Chillan, which had just unleashed an unexpected series of eruptive explosions. Just about to go in at the sharp end, roped up, on belay, clutching gas sensors and labouring to breathe through a respirator, the volcanic transcendence was apparent, as the previously-sceptical Yves bellowed: “Get your Supertrousers on! It’s business time!”

The Trail By Fire crew wishes to thank Cactus for their support, from the (not even frayed after 15 volcanoes) bottom of their Supertrousers. For more info on the expedition, check out