In early 2025, residents across Greece's Santorini, Amorgos, and Anafi islands felt the ground shake repeatedly for three months straight. Over 25,000 earthquakes rippled through the region, many strong enough to wake people at night. Now scientists have decoded what was happening beneath their feet: a river of molten rock, moving horizontally through the Earth like an underground current.
The magma was traveling through a channel 30 kilometers long, buried more than 10 kilometers beneath the seafloor between Santorini and the nearby Kolumbo volcano. To put the scale in perspective, researchers estimate the volume of magma could have filled 200,000 Olympic-sized swimming pools. As this molten material forced its way through layers of rock, it triggered each earthquake like a physical signature of its journey.
What makes this discovery remarkable isn't just what happened—it's how scientists figured it out. A team led by Anthony Lomax combined traditional physics with artificial intelligence to create a three-dimensional map of the tremors. Instead of treating each earthquake as an isolated event, they looked at the pattern the thousands of tremors created together. "The tremors act as if we had instruments deep in the Earth, and they're telling us something," Lomax explained. "The pattern those earthquakes make in our 3D model matches very well what we expect for magma moving horizontally."
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Start Your News DetoxThe magma never reached the surface. It got stuck in the crust, over 8 kilometers down, and gradually cooled. The seismic activity has now quieted. But this event has revealed something larger: a new way to understand what's happening inside volcanoes during periods of unrest.
Dr. Stephen Hicks from UCL sees the real potential ahead. "Whenever we see a cluster of earthquakes, that is data that can be used to work out the most likely cause," he said. By combining physics-based models with machine learning, scientists can now distinguish between different types of underground activity—magma movement, fluid shifts, rock fracturing—each leaving its own seismic fingerprint. This matters because volcanic regions around the world are home to millions of people. Better forecasting tools could give communities crucial warning time if an eruption becomes likely.
The Santorini swarm showed that the combination of traditional seismology and AI isn't just academic—it's already working, reading the Earth's signals in real time.
