Aseries of earthquakes near the Greek island of Santorini have led authorities to shut down schools, dispatch rescue teams with sniffer dogs and send instructions to residents including a request to drain their swimming pools.

Even though earthquake experts say the more than 200 tremors that have hit the area since early Friday are not related to the volcano in Santorini, which once produced one of the biggest eruptions in human history, locals are on edge.

The strongest earthquake recorded was magnitude 4.6 at 3.55pm on Sunday, at a depth of 14 kilometers (9 miles), the Athens Geodynamic institute said. A few tremors of over magnitude 4 and dozens of magnitude 3 have followed. There were no reports of damage or casualties.

Earthquake experts and officials from the Ministry of Climate Crisis and Civil Protection and the fire service have been meeting daily and decided to close schools Monday on the island of Santorini as well as nearby Amorgos, Anafi and Ios.

After Sunday’s meeting, they also advised residents and hotel owners in Santorini to drain their swimming pools over concerns that large volumes of water could destabilize buildings in case of a strong quake.

Another meeting was scheduled Sunday evening at the prime minister’s office with the chief of Greece‘s armed forces and other officials.

The fire service sent a contingent of rescuers including a sniffer dog on Saturday, and dispatched more forces Sunday, as a precaution. The rescuers have pitched tents in open fields.

Island residents have been advised to avoid large open-air events and to move about the islands mindful of rockfalls. All four islands have steep cliffs and, in the case of Santorini, a large part on the main town is built on a cliffside.

The picturesque volcanic island of Santorini, home to a tiny permanent population of approximately 15,500 people, attracted around 3.4 million tourists in 2023 alone

A shot of Oia, a coastal town on the northwestern tip of Santorini, famous for its iconic sunsets

Experts said it was impossible to predict whether the seismic activity could lead to a stronger tremor, but added that the area could potentially produce a 6 magnitude quake.

Mild earthquakes have also been recorded in Santorini’s volcano caldera, which is mostly undersea, since September. The strongest one with magnitude 3.8 occurred on Jan. 25. Since then, seismic activity inside the volcano has subsided, experts say.

The Santorini volcano eruption at about 1600 B.C. devastated the island, buried a town, and caused massive earthquakes and flooding that impacted the island of Crete and as far as Egypt. Experts estimate that up to 41.3 cubic kilometers (9.8 cubic miles) of rocks were ejected and 9-meter (29-foot) tsunamis hit Crete.

In the 1990s, the Santorini volcano was designated one of 16 volcanoes around the world that need to monitored because of past massive eruptions and proximity to dense population areas.

Athens, Feb 2, 2025 (AFP) – Greece’s tourist island of Santorini on Sunday braced for the prospect of more tremors after more than 200 small earthquakes shook the site of one of the largest volcanic eruptions in recorded history, prompting authorities to order school closures.

Some 200 minor earthquakes were recorded in the sea and surrounding islands in just 48 hours, with the strongest, of magnitude 4.6, striking the waters between Santorini and Amorgos on Sunday afternoon.

The spate prompted Greece’s civil protection late on Saturday to order schools closed down into Monday, while tents sprang up to house rescue teams sent to the island in response.

Authorities and experts said the tremors were triggered by tectonic rather than volcanic activity – dampening fears of a destructive eruption.

But with the surrounding seas home to several significant fault lines in the Earth’s crust, the possibility of a stronger earthquake to come could not be ruled out, said Kostas Papazachos, Professor of Geophysics at Thessaloniki Aristotle University.

“That is why there are some precautionary measures in place, precisely to limit the impact of a stronger earthquake,” Papazachos told ERTNews on Sunday morning.

“When you have a sequence next to you that is so vivid, so intense, you have to be a bit careful, precisely because there is always the risk of that happening.”

Greek authorities called for citizens to avoid large gatherings in enclosed spaces and stay away from certain ports of Santorini, derelict buildings and empty swimming pools of their water.

In case of a strong tremor, all citizens are called to get to high ground as far inland as possible.

The same measures are likewise in place for the neighbouring small islands like Amorgos.

Greece’s fire service in the southern Aegean Sea region was on general alert, while a rescue service team with a search dog, helicopter, drones was already at the scene.

An emergency meeting was scheduled for Sunday afternoon chaired by Prime Minister Kyriakos Mitsotakis.

Santorini is one of the most popular Greek islands with tourists. It has a population of just 15,500 but welcomed 3.4 million visitors in 2023, raising concerns over overtourism.

ATHENS, Feb 2 (Reuters) – Greek authorities have warned of an increase in seismic activity around the Aegean tourist island of Santorini, advising people to avoid four ports, empty their pools, refrain from gathering in indoor spaces and shut schools on Monday.

More than 200 tremors have been registered since Friday between the volcanic islands of Santorini and Amorgos, the civil protection ministry said in a statement on Sunday, citing experts tasked with assessing earthquake risks and monitoring Greece’s volcanic arc.

The experts, according to the ministry, have concluded that the tremors are not linked with volcanic activity and have proposed precautionary measures including the Feb. 3 school closures, which have been extended to the islands of Amorgos, Ios and Anafi.

They have urged people on Santorini to stay away from the small ports of Ammoudi, Armeni, Korfos and the harbour of Fira, which serves mainly cruise ships. Many of Santorini’s ports are surrounded by sheer rock faces.

In Athens, Prime Minister Kyriakos Mitsotakis chaired an emergency meeting on the issue, as Santorini authorities prepared for a potential evacuation.

Tents were set up in an outdoor stadium, police and the fire brigade were on alert and special disaster response units were on standby.

Greece sits on multiple fault lines and is often rattled by earthquakes.

Costas Papazachos, a professor of geophysics and seismology, who went to Santorini to assess the situation, said the measures were precautionary and the worst-case scenario was an earthquake measuring 6.0 or more.

“This does not necessarily mean that there will be a strong earthquake, it may well be that the thermal energy dissipates and we have a smaller earthquake in Santorini… But we have to take measures,” he told the Greek website protothema.gr

Santorini, with whitewashed buildings clinging to its steep cliffs and black-sand beaches, is visited by about 3 million people annually.

One of the largest volcanic eruptions in history, around 1600 BC, formed the island in its current shape. The last eruption in the area occurred in 1950. (Reporting by Renee Maltezou Editing by Sharon Singleton and Ros Russell)

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