She and her team flew these drones while inside the crater to compare distant atmospheric measurements with those closest to the source. They also used traditional ground sampling techniques to collect CO2 directly from the volcano’s gas vents.
With their drone data, the researchers found concentrations 23% higher than normal atmospheric levels, indicating that, despite measurements far from the source, the samples contained enough volcanic CO.2 that could distinguish it in the data. After accounting for the dilution, they confirmed that the amount matched their ground samples, showing that drones can work in place of in-person collection.
The team also measured the amount of CO2 was made up of carbon-13, a slightly heavier version of the element, which has 13 neutrons instead of the usual 12. They found that Poás had significantly higher carbon-13 content in 2019 than the data collected just a week before. explosion of 2017. It’s noteworthy, D’Arcy says, because it suggests carbon-13 levels could deplete just before eruptions and rise during quieter times, something that would be useful for tracking with future drone flights.
“Being able to use drones to sample these gases helps us get an idea of the mechanisms that could lead to an eruption and do it safely,” says Benjamin Jordan, a volcanologist at Brigham Young University-Hawaii who was not involved in work.
Drones, however, have their challenges: in Poás, D’Arcy’s team lost three. (One flew out of range and stopped responding to signals, and another’s rotor got tangled with its gas sampling apparatus and crashed. A third, sent to locate the second, just accidentally fell out of the sky. .) However, the equipment is relatively easy to replace, priced at a few thousand dollars each, cheap by research standards. “The cost of a human life is infinite,” says Jordan. “By using drones, you eliminate that risk.”
Researchers may never stop exploring the interior of volcanoes; it is undoubtedly dangerous, but the experience is also different from the others. “It’s very humiliating,” says de Moor, who makes his way to Poás about once a month. “An almost spiritual feeling because you don’t really feel like you belong here, in such a hostile environment.”
Imagine that one day, volcanic drone technology could resemble something out of a science fiction film: sophisticated, self-flying gadgets optimized to withstand the hellish conditions of Earth’s most violent eruptions. “And then,” says de Moor, “we’ll learn a lot.”