Santorini was hit by a powerful, shallow earthquake of 5.3 magnitude, which is the strongest to strike on the Greek island during recent seismic activity in the area.
The tremor was felt in Athens on Monday night and measuring a focal depth of 17 km (10.6 miles).
Residents of the neighboring island of Amorgos remain on the lookout after the last tremor, which followed a moderate earthquake of magnitude 5.0 between the islands on Sunday night.
The tourist hot spot has been shaken by seismic activities since January and over 12,800 earthquakes have been discovered by the seismological laboratory of the University of Athens.
Some residents have been seen patrolling dangerous areas to deter tourists to take pictures of rocks.
The landslides have occurred in many parts of Santorini due to the frequency and intensity of tremors and experts have not excluded much earthquake.
Seismologists were optimistic about the intensity of the earthquake, which were beginning to disappear, but now they worry that they were getting worse.
A state of emergency will remain in Santorini's place until at least 3 March.
Sunday's earthquake was preceded by three less than 4.0 magnitude, while the three on Monday morning was also more than 4.0.
The inspections did not find damage to buildings in Santorini or Amorgos.
As a result of earthquakes, no injuries were reported, which numbered thousands of January 26, but more than 11,000 people left the islands.
The schools will remain closed to Santorini, Amorgos and several other islands on Monday and Tuesday.
A team of the special disaster response department has set off for AMORGOS from Patras with a special rescue vehicle for earthquake, and technical teams are expected to check the electrical network of the island.
Costas Papazachos, a professor of seismology at the University of Aristotle in Thessaloniki, told the Greek television operator that the authorities should allow the situation to continue for most or throughout February.
“Let's hope we will slowly move on to a gradual de -escalation,” he said.
“We'll have to be a little patient and see. Let's hope that in a few weeks the phenomenon will start to go away.”
He said the possibility of a great earthquake was not completely excluded.
Meanwhile, the Viking cruise ship star, with 893 passengers and 470 crews, mooring at the SUDA port in Crete early on Monday morning.
This was to be the first cruise ship of the season in Santorini. The ship changed its route mainly to avoid the overpopulation of cars in Santorini during seismic activity.
The strongest quake so far has been a magnitude 5.2 on Thursday. Six or more are considered heavy.
Greece is one of the most likely to earthquakes in Europe, but scientists are puzzled by the current “clusters” of earthquakes that are not associated with great shock.
Santorini is what is known as the Hellenic volcanic arc, which is a chain of islands created by volcanoes, but the last major eruption is in the 50s.
The Greek authorities have said that recent tremor are related to the movements of tectonic plates, not volcanic activities.
Scientists cannot predict the exact moment, size or location of earthquakes.
From January 26 to February 8, 2025, the Seismology Laboratory (SL) of the University of Athens registered over 12,800 earthquakes in the Santorini-Amorgos area.
Additional reporting by Ruth Commerford.