The authorities in Greece on Monday closed schools and deployed emergency services on the Aegean island of Santorini, one of the country’s most popular tourist destinations, after the area was rattled by hundreds of minor and moderate earthquakes.
The ministry for civil protection said on Sunday that more than 200 tremors had struck the Aegean region between Santorini and Amorgos in the past 48 hours. They continued into Monday, shaking residents sometimes every few minutes. Precautions were also taken on several other islands affected by the tremors, with schools closed and emergency teams on standby.
Gerasimos Papadopoulos, a seismologist, wrote on Facebook that the quakes had been increasing in magnitude, calling them an “intense pre-seismic sequence.”
Prime Minister Kyriakos Mitsotakis, speaking from Brussels, where he is attending a meeting of European Union leaders, appealed to islanders to “be calm and follow civil protection orders.”
Most of the tremors were minor, but some exceeded magnitude 4.5, and Mr. Papadopoulos referred to readings of 4.7 and 4.9 in his Facebook post.
There were no reports of injuries, and only minimal damage, including minor landslides, was recorded by the authorities. Greece sits on multiple fault lines and is often rattled by earthquakes, but such a sequence of tremors growing in intensity is less common.
The Greek Organization of Earthquake Planning and Protection on Sunday advised islanders to avoid large gatherings in enclosed spaces, stay away from ports near cliffs and empty swimming pools to reduce potential damage to buildings. Emergency workers set up tents in outdoor sports venues, and the local authorities designated meeting points for potential evacuations.
The measures were precautionary, Greece’s civil protection minister, Vassilis Kikilias, said on Sunday, but he urged citizens to “strictly follow safety recommendations to minimize risk.”
The extent of that risk was unclear, with some experts playing down the potential for a major earthquake and stressing that the seismic activity was not linked to a dormant volcano on Santorini.
The chances of a much bigger and more damaging quake were “very small, that’s the extreme scenario,” Efthimios Lekkas, director of the earthquake planning organization, told Greek television on Monday. Referring to the potential for an eruption on Santorini, he said, “The volcano may awaken, but there’s no way we will have an explosion.” Mr. Lekkas said on Saturday that the volcano had produced very large eruptions only every 20,000 years.
The last one occurred more than 3,500 years ago, forming Santorini’s unique caldera, multicolored beaches and rock formations, which draw more than three million visitors annually. Since then the area has seen only a minor eruption, in 1950, that caused no casualties.
The island’s last major earthquake was in 1956, when a series of temblors of magnitude 7 to 7.7 killed 53 people and destroyed hundreds of homes.
Since then, no major tremors have occurred, though a series of smaller quakes also occurred during 14 months in 2011 and 2012, with shaking that diminished in intensity. Similar measures to those instituted this time around were not taken then, according to local officials.
In an interview with Volcano TV, a local station, on Sunday, Santorini’s mayor, Nikos Zorzos, said that the current precautionary measures, with emergency vehicles on the island’s roads, “might be excessive.” But he told national TV on Monday that the guidelines of expert committees should be followed.
Reports also suggested that thousands of people were looking to depart the island. Nonetheless, Mr. Zorzos said, “There is no mass exodus, some people are choosing to leave.”
Greek television on Monday showed dozens of cars waiting at Santorini’s main port, while Aegean Airlines said that it had added three additional flights from the island on Monday and Tuesday.
Mr. Zorzos had been due in Athens on Monday to open the island’s annual tourism campaign, an event that was canceled on Sunday night.
The impact on tourism on the island was unclear, though the British Foreign Office included the official warnings in its online travel advisory for Greece.
