An international team of scientists has developed a method that predicts the destructive potential of inactive volcanoes. The researchers used zircon, a tiny crystal found in volcanic rocks. He helped them estimate the amount of magma that could erupt if the dormant volcano woke up. The new method is reported by the journal Nature Communications.
Most active volcanoes on Earth are inactive – they have not erupted for hundreds or even thousands of years. Usually such volcanoes are not considered dangerous for the local population. A group of volcanologists from the University of Geneva (UNIGE), in collaboration with the University of Heidelberg in Germany, have developed a method that can predict the destructive potential of inactive volcanoes. Scientists used zircon, a tiny crystal found in volcanic rocks, to estimate the volume of magma in a dormant volcano.
A new method of analysis has been tested on the Nevado de Toluca volcano in Mexico. The results of the study make you nervous – up to 350 km3 of magma can erupt a volcano if it wakes up. This is roughly four times the total water stored in Lake Geneva. By the way, this is the largest lake in the Alps and the second largest lake in Central Europe.
Scientists noted that the new forecasting method is applicable to most types of volcanoes around the world.
What does it consist of?
UNIGE volcanologists have used a new approach combining zircon geochronology and thermal modeling. This helped them determine the amount of magma that the volcano could erupt.
“Zircon is a small crystal found in rocks erupted by volcanoes,” explains Gregor Weber, a UNIGE researcher and co-author of the study. Zircon crystals contain uranium and thorium. The decay of these radioactive elements allows us to determine the date of their crystallization. In addition, zircon crystallizes only within a certain temperature range. With these two parameters, we can determine how quickly the magma cools under the volcano. It’s like a saucepan of water – the larger it is, the longer it takes to cool. We have analyzed the zircons erupted by Nevado de Toluca over the past 1.5 million years, thus determining the evolution of magma temperature over time. This information is easily converted into potential magma volume using thermal modeling. ”
The new approach is twice as reliable as existing methods, the scientists conclude.