Volcán Lastarria was a milestone for Trail by Fire because it marked the end of our travels in the Andean Central Volcanic Zone, the belt of active volcanoes that runs through southern Peru and northern Chile. Ahead of us, we had the long drive south across the Pampean Gap to reach our next target volcano. This gap reveals something fundamental about how volcanoes in the Andes work, and why we’re here in the first place, but it requires a bit of explanation…
On the Trail by Fire, we couldn't get enough of Lascar. Literally -- we found it a challenge to collect enough volcanic gas. So we innovated and iterated, tackling the volcano time after time with our new tools. In the end, we climbed Lascar four times. In the process, we may have set some world records: longest improvised volcano gas collecting pole, and the highest flight of a quadcopter above sea level.
From the late seventeenth to the mid-twentieth century sulphur mining was flourishing in Chile. One of the most important sulphur deposits was found on the flank of Tacora volcano, the northernmost Chilean volcano, lying hard on the triple border with Peru and Bolivia. Sulphur mining on active volcanoes has been compared to hell on multiple occasions. In Chile, the miners not only had to deal with toxic gases and hard labour conditions, but also with the high altitude (>5000 m a.s.l.) and sub-zero temperatures. At Tacora, the sulphur was loaded and transported directly on a branch of the former Arica-La Paz steam-engine train line. This railway was the world's highest, with sections higher than 4800m a.s.l.
Dominating the skyline of Arequipa, El Misti is a big volcano. Although slightly smaller than Sabancaya in absolute terms (i.e. height above sea level, 5822 m compared to 5976 m), the lower surrounding terrain of El Misti makes it look a lot more formidable. Indeed, our Peruvian colleagues at OVI warned us (repeatedly!) that El Misti was the harder of the two to climb. Having only just made it to the top of Sabancaya without losing our breakfast, it would be a lie to say that we were thrilled at the prospect of attempting something even harder. In the end, it was Yves and Nial who took up the challenge, and began stuffing camping gear into rucksacks
After the exhausting ascent of Sabancaya, a day of rest was called for, and what better way to spend a day of rest than by carrying on working. Still based in Chivay (and still with our INGV and OVI colleagues) the team decided to head to the nearby Hualca Hualca volcano to investigate some fumeroles on its lower flanks.
There is some crucial information that we can't get from orbiting instruments – what is the composition of the gas, and exactly how much is being emitted? No one has answered these questions on Sabancaya. TBF was excited to find out – but it meant man-hauling our instruments to the top of this remote 5,976m (19,606) beauty.
Riding the Guallatiri high, we headed for Peru. We had aimed to be on Peruvian soil by noon, but it wasn’t long until Yves’ “facilitating” skills were put to the test. In fact, we were turned away once, and made a second attempt after diplomatic assistance from the incredible people at IRD. On the second try, border patrol scrutinized every nut and bolt in our load, with rules seeming to change by the minute. But after 6 hours and cobbling together some pesos from among the seats of the Land Rover, the team were in Peru!
After the hydrothermal loop, we felt ready to push higher onto the active volcanoes of the Andes. No better place to start than at the mighty Volcán Guallatiri, a 6100 metre high, actively degassing behemoth on the Chile-Bolivia border. Recently, this monstrous volcano gained fame by leaving the Top Gear trio and their 4x4s gasping for breath in the thin atmosphere at high elevation. All of The Trail By Fire team members were certain we could do better.
We took all precautions, considering that none of us (not even the Land Rover) had ever been so high. By carefully charting the elevation profile of the route in advance, we could monitor our health (e.g., heart rates) and the Land Rover’s performance, leaving opportunity for safe descent if the mission had to be aborted. The elevation profile from sea level at Arica could only be described as… “up”.
It quickly emerged that the ambitious route was no match for the Trail By Fire. We cruised through breathtaking vistas of the Parinacota region, fields of friendly alpacas and vicunias, and saline lakes with pink flamingos. Through it all, we adjusted well to the nuances of high-mountain commercial traffic on the Chilean-Bolivian route.
The Land Rover, fully loaded, easily shattered its design maximum altitude of 4500 metres. We ran out of navigable (off) road long before we ran out of power, and parked up comfortably at a plateau between snow-capped Parinacota and Guallatiri volcanoes, at about 5300 metres above the Pacific Ocean we had swam in only that morning.
Guallatiri’s last major eruption was in 1960, with another “probable” one (unconfirmed due to its remoteness) in 1985. In June-July 2015, the Chilean authorities (SERNAGEOMIN) briefly put Guallatiri on alert due to elevated seismic activity. The weather was perfect. A short ascent on foot provided a good vantage point on the active plume, and we engaged part of our “mobile volcano observatory" to make remote measurements of SO2 flux by UV Camera and DOAS. The UV Camera in particular performed spectacularly, yielding robust data for calculating volatile flux from this remote volcano.
With data now starting to roll in, and with the Land Rover and our bodies now tested to extreme altitudes, we are ready for the next step - crossing the border into Peru to embark on the most active and challenging leg of the Trail By Fire!