Scientists Unravel Mystery Behind Santorini’s Early 2025 Seismic Swarm
An international team of researchers, including several Greek scientists, has uncovered the underlying mechanisms behind the intense seismic activity recorded near Santorini, Greece, in early 2025. Their findings, published in the journal Science, identify a massive magmatic intrusion as the driving force.
The Scale of the Magmatic Intrusion
The study describes the intrusion as a vertical layer of magma that advanced in pulses over a span of more than 20 kilometers through the Earth’s crust. This process occurred at depths greater than 10 kilometers beneath the seafloor. Scientists highlighted the extraordinary scale of the event, estimating that the total volume of magma involved could fill about 200,000 Olympic-sized swimming pools.
“The seismic activity was unprecedented in its density and concentration within such a short timeframe,” the researchers noted.
Impact and Local Reaction
The 2025 seismic swarm included hundreds of detectable earthquakes, some registering above magnitude 5.0. The sudden intensity prompted emergency declarations, temporary school closures, and widespread concern among residents and tourists across Santorini and nearby islands.
Lingering Questions
During the height of the crisis, uncertainty persisted among both scientists and local authorities. Experts debated whether the tremors indicated volcanic unrest — a precursor to a potential eruption — or resulted from tectonic fault movement that could foreshadow a larger earthquake, possibly similar in scale to a magnitude-7 event.
Related Research
Earlier studies had also suggested a possible shift of magma between Santorini and the nearby Kolumbo volcano, which may have contributed to the seismic sequence observed in early 2025.
“This was a globally exceptional seismic event in both its scope and its underlying geological mechanism.”
Author’s summary: The 2025 Santorini seismic swarm was caused by a vast magmatic intrusion moving through the crust, triggering hundreds of earthquakes and renewed concerns about volcanic hazards in the region.