Greek Prime Minister Kyriakos Mitsotakis has urged people on the island of Santorini to “stay calm” after an increase in seismic activity.
His remarks come as schools were told to close on Monday and authorities advised against large gatherings in enclosed spaces across the island, a popular tourist destination known for its whitewashed buildings and blue-domed churches.
More than 280 earthquakes were recorded across Greek islands in the past 48 hours, according to the University of Athens’ Seismological Laboratory.
Tremors of up to 4.9 in magnitude were recorded north-east of Santorini on Monday, while there have been quakes of 4.3 and 3.9 magnitude reported nearby in recent days.
Speaking from EU talks in Brussels, the prime minister said the country is working to manage “a very intense geological phenomenon”, adding that he has asked the authorities to provide a “comprehensive presentation” of the geological data, to ensure everyone knows the scale of this seismic event.
Mitsotakis’s remarks come as many people in Santorini spent Sunday night outdoors, amid fears of potential damage to buildings during the quakes.
Some focal points of the tremors have been recorded at a depth of just 2km (1.2miles) below the surface.
Some residents have chosen to leave the island while the seismic activity is ongoing, including Kostas Sakavaras, a tour guide who has lived there for 18 years, and his wife and children.
“We decided yesterday to take the ferry and come to the mainland,” he told BBC News.
“We stayed calm. It’s not such a big deal. It was more like, the schools were closed. We considered it’s a better choice to come to the mainland as a precaution.”
He said they were keeping in touch with friends and family who had remained, and that the tremors had been “mild”.
“Nothing has been falling, or anything like that,” he said, adding that the worst part had been the sound.
“That’s the most scary part of it,” said Mr Sakavaras, who plans to return home once schools reopen.
Santorini is on what is known as the Hellenic Volcanic Arc – a chain of volcanic islands created by plate tectonics – but the last major eruption was in the 1950s.
Greek authorities said that the recent minor earthquakes were related to tectonic plate movements instead of volcanic activity.
The tremors are being caused by the Aegean sea plate subducting beneath the African plate, causing resistance and friction to build up along the fault line.
When the plate shifts, energy is released in the form of an earthquake.
Earthquakes are very common in this region, but authorities say activity in the Santorini caldera – the volcanic basin the island sits around – remains in decline.
While the recent tremors are thought to be unlikely to be a precursor to a volcanic eruption, the possibility cannot be ruled out.
The tremors recorded by geologists are considered minor, but authorities have recommended a number of preventative measures in addition to the school closures, including asking ships to avoid the ports of Ammoudi and Fira.
Big cruise ships often anchor near the Old Port of Fira, with passengers being brought to shore on smaller boats.
Schools were also told to close on the nearby islands of Anafi, Ios and Amorgos, and will remain so until 7 February.
On Monday, a message from the emergency services was sent to the residents of Santorini, urging them to leave the areas of Ammoudi, Armeni and the Old Port of Fira due to landslides.
According to the European Mediterranean Seismological Centre, a total of over 555 earthquakes have been recorded since January 28 in the area between Amorgos and Santorini.
Kostas Papazachos, a professor of geophysics at Thessaloniki Aristotle University, told public broadcaster ERT that the precautionary measures were “precisely to limit the impact of a stronger earthquake”, as quakes cannot be predicted.
He added: “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 something like that happening.”
Earthquakes are measured on the Moment Magnitude Scale (Mw) – instead of the better-known Richter scale, which is now considered less accurate. The number attributed to an earthquake represents a combination of the distance a fault line has moved and the force that moved it.
A tremor of 2.5 or less usually cannot be felt, but can be detected by instruments. Quakes of up to five are felt and cause minor damage.
Prof Papazachos said that were a minor earthquake to occur while people were gathered in large crowds, it could create panic that may lead to people being injured.
The South Aegean Regional Fire Department has been placed on general alert and rescue teams as well as the regional commander have been dispatched to Santorini.
Various airlines have added extra flights as people rush to leave the island, and more ferries have also been deployed. Hotel owners are reporting a series of cancellations in their bookings, as tourists are avoiding the island.
Though the island has a population of around 15,500, it welcomes millions of tourists each year.
