University of Georgia

Research finds link between CO2, big volcano eruptions

Tungurahua Volcano eruption at night, with snow, Ecuador
Tungurahua volcano erupts at night in Tungurahua, Ecuador. (Photo by pxhidalgo/iStock)

Volcanologists from the University of Georgia and two Swiss universities found a link between carbon dioxide and the volume of gas trapped in magma, which could help predict the intensity and magnitude of a volcanic eruption. Higher levels of CO2, they found, lead to an increase in the total volume of gas in magma, which may result in violent, explosive eruptions.

The new findings could one day lead to better early-warning systems for people who live in the vicinity of volcanoes, though the study’s lead author, Mattia Pistone, cautioned that much additional work is needed for such a practical application.

Pistone, an assistant professor of geology in the Franklin College of Arts and Sciences at UGA, worked with Luca Caricchi from the University of Geneva and Peter Ulmer from the Swiss Federal Institute of Technology to determine the role that gas geochemistry plays in the volume of gas stored in magma by simulating what happens in magma chambers prior to volcanic eruptions.

“This produced a true, original result,” Pistone said. “If you have more CO2 in the magma, then that will increase the volume of gas stored in the magma. Adding more CO2 in the magma implies bad news in terms of volcanic hazard.”

Pistone and his fellow investigators formulated their research question after observing “strange” and unexpected data from a previous project, he said. The researchers compared CO2-rich magma with water-rich magma, observing that magma rich with CO2 led to an increased volume of gas stored in magma prior to volcanic eruptions.

“Gaseous CO2 favors the presence of gas bubbles that tend to remain trapped in the magma,” said Pistone, whose “Magma Mia lab” will test pre-eruptive conditions of volcanoes. “If you increase the CO2 content—which increases the volume of gas in the magma—the volcano is not going to erupt gently. It’s going to erupt explosively.”

The amount of CO2 stored in magma depends on a few factors, including the magma’s physical composition, the volcano’s location on Earth and the architecture of the volcanic system.

With the researchers’ findings, volcanologists could now consider the effect of gas geochemistry when trying to determine the intensity and magnitude of a volcanic eruption in the future.

“I hope there will be a new debate among volcanologists, where what we achieved experimentally can be further confirmed in the near future by studies in the field with new data,” Pistone said. “I hope there’s a ripple in volcanology to rephrase research questions and address new research lines, providing new insights on how to investigate active volcanic systems.

“Laboratory simulations capture only a few aspects of the more complex natural volcanic scenarios and cannot be used directly in how we assess volcanic hazard and risk,” Pistone said. “I hope the impact of my research can be relevant in this.”

The researchers’ study was recently published in Terra Nova, a peer-reviewed geology and planetary science journal.