A newly discovered way to monitor magma movements beneath Mount Etna could help scientists forecast when it might erupt.
Mount Etna, located on the Italian island of Sicily, is Europe’s largest active volcano.
Mount Etna sits in the collision zone between the African and European tectonic plates.
The crust beneath Mount Etna is up to 19 miles (30 km) thick.
This method could help experts estimate the timings of eruptions at Mount Etna.
With the use of a recently developed method for tracking magma movements beneath Mount Etna, scientists may be able to predict when the volcano will erupt.
Mount Etna is the biggest active volcano in Europe, and it is situated on the Italian island of Sicily. Although humans have only been recording its activity for the last 2,700 years, the volcano has been erupting for up to 500,000 years.
In June 2025, Etna’s most recent eruption caused an avalanche of hot lava blocks and other debris in addition to ejecting a massive ash cloud that was four miles (6.5 kilometers) high. Though forecasts aren’t always accurate, officials were able to issue warnings the morning of the eruption because it was anticipated.
The new technique might help forecast the eruptions of Mount Etna. The b value, which characterizes the proportion of low-magnitude to high-magnitude earthquakes in a region of the Earth’s crust, was examined in a recent study by researchers at Italy’s National Institute of Geophysics and Volcanology (INGV). According to a study published in October, this ratio may alter as magma rises through the crust to a volcano’s summit. 8 in the Science Advances journal.
Marco Firetto Carlino, a geophysicist at INGV’s Etna Observatory and the study’s lead author, told Live Science via email that “changes in the b value over time reflect how the stress inside the volcano is evolving.”. “Tracking the b value can help reveal different stages of magma transfer from depth to the surface because magma ascent causes stress changes within the crust. “.
The researchers used an updated statistical model to investigate the b value, a well-known parameter in volcanology, in a novel way. According to Firetto Carlino, they discovered a “very strong” correlation between the b value and Etna’s volcanic activity after assembling 20 years’ worth of Mount Etna earthquake data.
The African and European tectonic plates collide where Mount Etna is located. The study found that the volcano is based on a strike-slip fault, a vertical fissure in the Earth’s crust that makes it easier for magma to rise to the surface.
Mount Etna is surrounded by a crust that is up to 19 miles (30 km) thick. Before an eruption, magma rises through this volume, but the molten rock feeds a network of interconnected storage zones that are embedded in the crust at varying depths rather than refilling a single magma chamber.
“It feeds an intermediate storage system with different zones probably extending 2 to 4 miles (3 to 7 km) deep.” Firetto Carlino explained that the deepest magma storage zone is 7 miles (11 km) below sea level. The final storage zone, which is situated inside the volcano structure above sea level, is reached by rising magma after passing through a complex web of fissures.
Because of Etna’s regular activity, the researchers had a lot of data to work with and extract b values from. The 19 miles of crust beneath the volcano were examined for seismic patterns between 2005 and 2024, with special attention to how these patterns differed between crustal regions.
Since there are more small earthquakes in active zones than large ones, areas of the Earth’s crust with active magma storage zones typically have higher b values than more stable regions.
Firetto Carlino explained, “This occurs because rocks impacted by moving magma become weak and highly fractured.”. For instance, volatiles released by magma within a storage unit seep into the nearby rocks, facilitating the slipping of tiny fractures. “,”.
On the other hand, because it takes more force to break the rock, larger earthquakes tend to occur in more stable areas of the Earth’s crust. According to Firetto Carlino, “rocks with good mechanical properties can store stress for longer periods of time.”. “When they do break, the resulting earthquakes are larger and have lower b values. “.”.
Researchers might therefore be able to trace the movement of magma through the deep crust to the first storage zone, up from there to the intermediate storage system, and up again to the shallow storage zone by monitoring the b value over time. Experts may be able to predict Mount Etna eruption timings with the use of this technique.
“Tracking the movement of magma in the crust and evaluating the volcano’s changing condition prior to eruptions can be effectively accomplished by monitoring the b value,” Firetto Carlino stated.
Because of its vast seismic catalog and layered magma storage zones, Mount Etna was a good test site for the study, but the findings may also be applicable elsewhere.
“If a sufficient number of earthquakes are available and their locations are dispersed across various crustal sectors, well constrained by previous geological studies, the b value could also be used, in principle, to track magma movements in other volcanic areas,” Firetto Carlino stated.
