The intense swarm of tens of thousands of earthquakes that rattled the Greek islands earlier this year was driven by a massive, horizontal river of magma forcing its way through the Earth’s crust, according to a groundbreaking new study.
Researchers determined that over a three-month period, a volume of molten rock equivalent to 200,000 Olympic-sized swimming pools traveled horizontally through a 30-kilometer-long (19-mile) underground channel. This “magma intrusion,” located more than 10 kilometers beneath the seafloor, shattered surrounding rock and triggered more than 25,000 tremors, many strong enough to be felt and to cause tourist evacuations.
The scientific team combined advanced physics with artificial intelligence to analyze the seismic data. By using each tremor as a virtual sensor, they created a detailed 3D model of the event, mapping the precise movement and stress within the crust.
“The pattern those earthquakes make in our 3D model of the Earth matches very, very well what we expect for magma moving horizontally,” explained lead author Anthony Lomax, a research geophysicist.
The findings, published in the journal Science, reveal that the magma moved from a source beneath the Santorini and Kolumbo volcanic systems toward the island of Anydros. The 2025 seismic crisis had sparked fears of a repeat of the region’s devastating 1956 earthquake or a potential eruption of the Kolumbo submarine volcano.
Dr. Stephen Hicks from UCL, a lead researcher on the study, highlighted the broader implications: combining physics and machine learning in this way provides a powerful new tool that could significantly improve our ability to forecast volcanic eruptions in the future.
By James Kisoo
