Estimates of carbon dioxide (CO2) emissions from volcanoes may have been significantly underestimated, according to new research by The University of Manchester.
Published in the journal, Science Advances, scientists have developed an advanced sensor that can detect volcanic gases with rapid speed and precision.
Using the sensor mounted on a helicopter, the research team measured emissions at Soufrière Hills Volcano on the Caribbean Island of Montserrat, revealing that the volcano emitted three times more CO2 than earlier studies had estimated.
Scientists typically monitor volcanic emissions by focusing on hot vents, known as fumaroles, which release high concentrations of easily detectable acid gases like sulphur dioxide (SO₂) and hydrogen chloride (HCl). However, many volcanoes also have cooler fumaroles, where water-rich hydrothermal systems on the volcano absorb the acidic gases, making them harder to detect. As a result, CO₂ emissions from these cooler sources are often overlooked, leading to significant underestimations in volcanic gas output.
The new technology exposes those hidden emissions, offering a more accurate quantification of the volcanoes gas output.
The findings also have significant implications for volcano monitoring and eruption forecasting.
Alexander Riddell, lead researcher from The University of Manchester, said: "Volcanoes play a crucial role in the Earth's carbon cycle, releasing CO₂ into the atmosphere, so understanding the emissions is crucial for understanding its impact on our climate. Our findings demonstrate the importance of fast sampling rates and high precision sensors, capable of detecting large contributions of cooler CO2-rich gas.
"However, it's also important to realise that despite our findings that CO2 emissions could be around three times higher than we expected for volcanoes capped by hydrothermal systems, volcanoes still contribute less than 5% of global CO2 emissions, far less than human activities such as fossil fuel combustion and deforestation."
Mike Burton, Professor of Volcanology at The University of Manchester and co-author, added: "Development of high-sensitivity high-frequency magmatic gas instruments opens up a new frontier in volcanological science and volcano monitoring. This work demonstrates the new discoveries which await us. By capturing a more complete picture of volcanic gas emissions, we can gain deeper insights into magma movement, observe potential signs of impending eruptions and signs that an ongoing eruption might be ending. For the people living near active volcanoes, such advancements could enhance early warning systems and improve safety measures."
The research was carried out in collaboration with Montserrat Volcano Observatory and the National Institute of Optics, Firenze, Italy. Now, the study team are searching for funding to make this instrument suitable for unmanned aerial vehicle platforms, opening up new opportunities for performing delicate gas measurements in challenging and hazardous environments.
This research has been published in the journal Scientific Advances.
Full title: Quantification of Low-Temperature Gas Emissions Reveals CO₂ Flux Underestimates at Soufrière Hills Volcano, Montserrat.
DOI: https://doi.org/10.1126/sciadv.ads8864
