Unusually intense seismic activity in the southern Aegean in a sea region roughly between the islands of Santorini, Ios, Amorgos and Anafi, including numerous recent tremors between 3 and an up to 4.9 on the Richter scale, has activated civil defense authorities in the country and also attracted heightened international interest.

Santorini has generated the most attention, given that it’s a volcanic isle that’s possibly the best-known site in Greece after the Acropolis.

Media scrutiny this week focused on its Thera volcano, and on whether – and to what degree – volcanic activity is responsible for the seismic surge.

The Caldera, in the narrow strait between arc-shaped Santorini and the smaller rocky isle of Thirassia, is an iconic backdrop for holiday photos, social media “selfies” and even wedding pictures. The Caldera itself was created by a cataclysmic volcanic eruption in the 16th century BC that’s considered responsible for the destruction of the Minoan civilization on the nearby large island of Crete. More than a millennia later, Plato’s mention of the lost civilization of “Atlantis” launched nearly two and a half millennia of speculation, replete with artwork, literature and exploration.  Santorini, whose ancient name is Thera, has long been considered as one of the “top picks” for the philosopher’s inspiration.

FILE PHOTO: A drone view shows the village of Oia, on Santorini, Greece, May 8, 2020. REUTERS/Alkis Konstantinidis/File Photo

Returning to the 21st century, and specifically this week, two well-known Greek researchers touched on whether the seismic activity in the specific sea region and islands emanates from the Santorini volcano and its lesser known but much more active “twin”, the submarine volcano of Kolumbo. The latter is located roughly eight kilometers northeast of Cape Kolumbo, also on Santorini.

A pair of well-known scientists, Akis Tselentis, an oft-cited University of Athens seismology professor, as well as Costas Synolakis, the secretary of the Athens Academy’s division of natural sciences and a celebrated USC civil and environmental engineering professor, this week appeared to diverge, to a certain degree, with several peers in Greece and abroad, who maintain that the quakes are the byproduct of tectonic shifts in the plates of the earth’s crust, and not due to volcanic activity in the southern Aegean.

Tselentis took to Facebook on Monday to first state that “volcanos are active, even if some want them to be dormant. I hope I am wrong.”

He continued by expressing an opinion that the current seismic activity “is, in high probability, a pre-seismic sequence.”

“…As to whether the (seismic) action has anything to do with the volcano, I have one thing to say. Could it? When magma rises and increases the stresses in the fault zones, then some local faults are activated, which then, through a domino effect, activate others? I read opinions yesterday by foreign seismologists. In any case, volcanoes are active, even if some people want them to be dormant. I hope I’m wrong,” he said.

Passengers board a ferry as they leave following high seismic activity, on the island of Santorini, Greece, February 3, 2025. REUTERS/Nikos Christofakis

On his part, Prof. Synolakis, who also holds a department seat at the University of Crete, told a radio program on Monday that “…there are three different possibilities or scenarios… one possibility is that a fault has been activated, something similar to the fault that caused the major earthquake of 1956. In other words, a continuation of that fault. That was the earthquake that reached 7.5R. But if there is an earthquake now, I don’t think anyone expects it to be that big. So that’s one scenario,” he said, adding:

“The other scenario is an activation of the volcano that is inside the Caldera … while the other scenario is an underwater volcano called Kolumbo, which is just north of Santorini, about between 5 and 8 kilometers from the northern tip of Santorini, so going towards Ios. There’s an underwater volcano there called Kolumbo. So, these are the three scenarios and the possible effects they could have. That’s what was examined in this area.”