Hidden magma movements behind mysterious Santorini earthquake swarm, AI study reveals
Researchers discovered that the tremors in Greece were not caused by a slipping fault but were triggered by rebounding sheets of magma slicing through the Earth’s crust.
Security footage from a bar in Dalyan, Turkey, shows the 5.8-magnitude earthquake that hit parts of Turkey and Greece on June 3. The video shows glasses, a blender, and various bottles of liquor shaking during the earthquake.
More than 25,000 earthquakes rattled the Greek islands earlier this year, sending residents fleeing and prompting tourists to reconsider their vacation plans. According to a new AI-powered study, the pulsing movement of a massive underground magma pool was behind the mysterious earthquake swarm.
The international study, led in part by scientists from University College London (UCL) and published Thursday in the journal Science, used artificial intelligence to analyze the seismic data from between Santorini and nearby Amorgos. Researchers found that the tremors were not the result of a typical fault slip but were instead caused by rebounding sheets of magma slicing through the Earth’s crust about 7 miles (12 kilometers) below the seafloor. This deep magma activity triggered bursts of quakes, some approaching magnitude 5.
Broken construction, an empty pool and Nea Kammeni islet on the Greek island of Santorini on February 21, 2025. A decrease in seismic activity has been recorded around the Greek island of Santorini, a popular tourist destination in the Aegean Sea known for its iconic whitewashed cube-shaped architecture. (Photo by Nikos Oikonomou/Anadolu via Getty Images)
The swarm, which struck in January and February, caused widespread concern and led to school closures and a local state of emergency as residents feared a possible volcanic eruption or major quake.
Traditional monitoring methods failed to detect the movement due to its depth. To overcome this, the research team employed machine learning to detect and locate over 25,000 quakes, then applied 3D imaging techniques to map the geologic source of the unrest, according to a university news release.
Researchers estimate these magma intrusions, known as dikes, contained enough molten material to fill 200,000 Olympic-sized swimming pools.
So, why didn’t this magma reach the surface and erupt? The team found that the magma lacked the pressure and buoyancy needed to break through the crust.
The study offers new insights into how deep magma movement can drive intense seismic activity without necessarily signaling an impending volcanic eruption.
Chinese tourists are seen behind a police ribbon forbidding the entrance to the areas considered dangerous in case of earthquakes and landslides in Oia village of Santorini Island, Greece on February 21, 2025. (Photo by Nikos Oikonomou/Anadolu via Getty Images)
“Our technique could be applied to future earthquake swarms almost in real time and could allow us to better forecast the likelihood of volcanic eruptions or larger earthquakes,” said study co-author Dr. Stephen Hicks with UCL’s Department of Earth Sciences.
While the technique may one day help predict eruptions, Hicks noted that in this case, the magma remained far below the surface.
“Our evidence suggests the magma causing the Santorini earthquakes wasn’t getting close to the surface,” Hicks said. “If we apply our technique to similar swarms of earthquakes in future, we could pinpoint where the magma would likely come out and potentially the amount.”
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