By studying magma and its gas composition, it is possible to predict when volcanic activity is increasing.
A study published in Nature and carried out by scientists at the University of Tokyo which, after 7 years, manages to give us back important evidence. What has been published, in fact, is a new method for examining the gaseous composition of magma and the ratio of specific atoms of its gases. Specifically, the method predicts observations in the changes in the ratio of argon-40 to helium-3 .
Professor Hirochika Sumino of the Research Center for Advanced Science and Technology and co-author of the study explained in a press release: ‘We knew that the isotope ratio of helium occasionally changes from a low value, similar to that of helium found in the Earth’s crust, to a high value, such as that of the Earth’s mantle, when magma activity increases .”
To get more information, Sumino and his team monitored the gases from six fumaroles around the active volcano Kusatsu-Shirane, about 150 kilometers northwest of Tokyo. The researchers collected gas samples over seven years between 2014 and 2021. Once in the laboratory, they analyzed them using the noble gas mass spectrometer . This allowed isotopic compositions, such as those of helium-3, to be accurately measured.
The researcher argues that the amount of gas present under the volcano is what generates the phreatic eruption which is the name given to the phenomenon of the increase in water pressure of a volcano’s water system, or what triggers an eruption.
Sumino’s new goal is to be able to use a “field” spectrometer , in order to perform the same analysis on gases, but in real time and in the field. “We want to be able to detect changes in magma activity as soon as possible,” Sumino said. “We are now developing a portable mass spectrometer for real-time, on-site monitoring of noble gas isotope ratios in fumarolic gases. Our next step is to establish a noble gas analysis protocol with this new tool, to ensure that all active volcanoes – at least those that have the potential to cause disasters to local residents – are monitored 24 hours a day , seven days a day. seven”.
- Monitoring of magmatic–hydrothermal system by noble gas and carbon isotopic compositions of fumarolic gases. (nature.com)