A group of international scientists revealed that the heightened earthquake frequency in Santorini at the dawn of 2025 was due to an enormous vertical magma column, the volume of which could have filled up a space equivalent to 20 large Giza Pyramids in Egypt.
The research team, which included a group of Greek scientists, published their findings in Science magazine and estimated that the magma column had penetrated over 20 kilometers inside the Earth’s crust.
The team estimates that the volume of magma involved was so large that it could fill nearly 200,000 Olympic-size swimming pools or amount to 200 times the volume of the Great Pyramid of Giza. They add that this quantity would be enough to cover Manhattan or the islands of Bermuda with a layer of magma about 9 meters thick.
The seismic swarm—marked by hundreds of noticeable earthquakes, some above magnitude 5—occurred within a very short time span. “It triggered a local state of emergency, school closures, and alarm among residents and visitors,” the researchers note. At the same time, there was uncertainty over whether the tremors were linked to volcanic activity or to the slipping of tectonic faults, similar to the one that caused the devastating 7.7-magnitude earthquake of 1956.
The findings suggest that this wave-like process of magma transport is not unique to Santorini but represents a fundamental mechanism beneath volcanoes worldwide. The methods developed, the researchers emphasize, can help monitor similar crises in near real time, especially in areas where activity occurs far offshore or deep underground, beyond the reach of standard measuring instruments.
“Santorini, part of the Hellenic Volcanic Arc, has a history of catastrophic eruptions, including the ‘Minoan eruption’ around 1620 BC,” the researchers note. Although the 2025 crisis did not lead to an eruption, it highlights the risks for residents and the importance of continuous, high-resolution geophysical monitoring.
