Speaking to the Lusa news agency, one of the authors, Fátima Viveiros, explained that the research allowed for the first time to quantify the CO2 emitted by the three fumarole fields of Fogo: Caldeira Velha, Caldeiras da Ribeira Grande, and Pico Vermelho.

"What we can conclude is that even dormant volcanic areas, that is, potentially active, can emit quite high amounts of carbon dioxide, on par with active, erupting volcanoes," she stated.

The study brought together researchers from the Azores Seismovolcanic Information and Surveillance Center (CIVISA), the Institute of Volcanology and Risk Assessment (IVAR) at the University of the Azores, and the Department of Earth Sciences at the University of Palermo (Italy).

To calculate the CO2 levels emitted by the volcano located in the central area of the largest Azorean island, the scientists used a "technique developed by the University of Palermo" applied to the Solfatara volcano (near Naples).

The study, published in the scientific journal 'Applied Geochemistry', with Fátima Viveiros, António Cordeiro, and Alessandro Aiuppa as authors, estimated that the Fogo volcano emits approximately 232 tons of CO2 per day.

"When we add up the contribution of the three Fogo fumarole fields, we see values above 200 tons of carbon dioxide per day, and this is comparable even to the carbon dioxide emissions of some volcanoes in South America that experience frequent volcanic activity," she compared.

Despite these values, Fátima Viveiros emphasized that the emissions do not pose a public health problem because the "gas is diluted in the atmosphere," noting that access to the fumarole fields is "limited."

"The fumarole fields, in terms of accessibility and health exposure, as they currently stand, and if visitors follow the rules—and this is crucial—do not pose health problems," she reinforced.

The professor at the Faculty of Science and Technology of the University of the Azores highlighted the importance of research for "monitoring the volcanic system," since the amount of CO2 represents a "major indicator" that "is important to understand" to detect "potential changes."

Calculating the amount of CO2 emitted is "equally important" due to climate change, she noted.

A study will also be developed to quantify the levels of CO2 emitted by the Furnas volcano on São Miguel Island, followed by studies in all fumarole areas of the Azores.

The study was carried out as part of the MAGAT research project - 'from MAGma to ATmosphere'.

The Fogo volcano, also known as the Serra de Água de Pau volcanic massif, has a caldera at its summit, Lagoa do Fogo, which is one of the most famous landscapes in the Azores.