Volcanic eruptions cannot be predicted with 100 percent certainty. However, the details of an upcoming eruption can be estimated using the hot, foul-smelling gases produced by the volcano.
These gases provide clues about the timing, duration, or severity of upcoming eruptions that can help local authorities determine if and when surrounding communities need to evacuate.
On average, there Up to 50 volcanoes Actively erupt on the planet at any time. Many of these volcanoes are more likely to emit hot gases – such as steam and carbon dioxide – than lava. Synthesizing these gases is key to understanding the mysterious ways volcanoes, but they can be dangerous.
Currently, Drones make it safer And easier than ever.
For the better part of the past decade, I’ve been visiting such gas volcanoes regularly to capture them before, during, or after an eruption.
I’ve worked with other scientists and engineers Measurement of volcanic gases With a variety of devices connected to the drones.
Our latest research uses drones to Capturing volcanic carbon dioxide at the Boa volcano in Costa Rica. We measured the carbon isotopes of carbon dioxide and discovered a pattern in the way that chemical fingerprints change during different stages of activity.
Unique carbon makeup
Carbon dioxide is everywhere: in the air we take out, in vehicle exhaust – and dissolved in magma. At volcanoes, magma escapes to the surface through fissures and hydrothermal systems (such as geysers in Yellowstone National Park), by seeping through the soil or by blowing into a column of gas.
By getting a sample of this volcanic carbonwe can measure the stable carbon isotope ratio, a unique chemical formula that reflects the source and path carbon dioxide took to the surface.
Every volcano around the world produces a unique combination of these Carbon isotopes that change when the volcanic system changes.
However, it took a long time to collect each sample when the researchers needed to hike into the crater, putting them at risk every second they remain in the danger zone. With the development of unmanned aerial systems (UAS, also known as drones), researchers have begun to send these machines into danger zones.
Use of drones
To do this, we used switches and electronic parts to connect the gas sensors to the communications systems on board the drones. Volcanic carbon dioxide will be sucked up through a series of tubes with the help of a pump and sensors that send a signal to the pilot when we entered the gas column. With the push of a button on the remote control, the pilot can choose – from a safe distance – when and where to collect the gas sample.
We arrived in Costa Rica in April 2019 with our shiny new drone installation, which we launched over the edge of the Poás Volcano and which crashed almost instantly. Fortunately, our team came up with a quick fix for the second drone – a pump and switch hanging from the drone in a wash bag. It worked flawlessly.
To avoid further losses, we approached the hole and assembled our group just above it. Later that day, we looked at the stable isotopes of carbon in the drone samples and in samples we took from Earth. After we accounted for mixing with normal air in the drone samples, the results were strikingly similar. Our drone assembly worked!
When we started compiling our data using all of the carbon isotopes that had been measured at Poás volcano in the past, we noticed a trend in how the isotopic balance shifted when the volcano was behaving differently.
During volcanic phases, when Poás was making wet eruptions releasing extremely hot, sulfur-rich gas, the carbon isotopes declined to lighter values. Meanwhile, during the quieter phases When the volcano was closedisotopic equilibrium increased to heavier values.
With this new vision, we can look back even more and bring our data together Isotope data from an older activity. We have seen that this pattern has been repeating itself, with carbon isotopes alternating between heavy and light values over the past 20 years of activity in Poás. There were relatively heavy values when the volcano was closed and there were relatively light values when the volcano was open.
We now have a blueprint for warning signals to look for in future carbon isotopes sampled at this volcano as it prepares to erupt.
Thanks to drones, we’ve been able to capture the first carbon dioxide from the Poás volcano since 2014. Brave volcanologists have taken all the volcanic gases sampled before our work manually by brave volcanologists climbing into the Poás crater. These campaigns were few and far between.
Hopefully, with the start of gas-capturing drones, carbon dioxide is in volcanoes Frequent sampling can be started. This will fill in the gaps in the timeline and help us understand and predict volcanic eruptions.