Greece is preparing for earthquakes when shaking shakes Santorini and other islands

Greece authorities closed schools on Monday and released relief services on the Aegean island of Santorini, one of the country’s most popular tourist destinations after the area was rattled by hundreds of smaller and moderate earthquakes.

The Ministry of Civil Protection said on Sunday that more than 200 shivers had hit the Aegean region between Santorini and Amorgos for the past 48 hours. They continued into Monday and shake residents sometimes every few minutes. Precautions were also taken on several other islands affected by shaking, with schools closed and emergency teams in standby.

Gerasimo’s Papadopoulos, a seismologist, wrote on Facebook that the earthquakes had risen in size and called them an “intense pre-ensommic order.”

Prime Minister Kyriakos Mitsotakis, who spoke from Brussels, where he attends a meeting with EU leaders, appealed to islanders to “be calm and follow civilian protection orders.”

Most of the shake was smaller, but some exceeded the size 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, were registered by the authorities. Greece sits on several error lines and is often rattled by earthquakes, but such a series 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 closed spaces, stay away from ports near rocks and empty swimming pools to reduce potential damage to buildings. Emergency workers created tents in outdoor sports sites and the local authorities appointed meeting points for potential evacuations.

The measures were caution, said Greece’s Civil Protection Minister, Vassilis Kikilias on Sunday, but he urged citizens to “strictly follow security recommendations to minimize the risk.”

The extent of this risk was unclear, with some experts who played the potential for a major earthquake and emphasized that the seismic activity was not linked to a sleeping volcano on Santorini.

The chances of a much larger and more harmful earthquake were “very small, it is the extreme scenario,” Ephimios Lekkas, director of the earthquake planning organization, told Greek TV on Monday. With reference to the potential of an outbreak on Santorini, he said, “The volcano can wake up, but there is no way we want an explosion.” Mr. Lekkas said on Saturday that the volcano had only produced very large outbreaks every 20,000 years.

The last happened more than 3,500 years ago and formed Santorini’s unique Caldera, multicolored beaches and rock formations that draw more than three million visitors annually. Since then, the area has only seen a minor outbreak in 1950 that caused no loss.

The island’s last major earthquake was in 1956 when a number of Temblors of Magnitude 7 to 7.7 killed 53 people and destroyed hundreds of homes.

Since then, no major shaking has taken place, although a number of smaller earthquakes also occurred over 14 months in 2011 and 2012, with the shaking that was diminished in intensity. Similar measures for those introduced this time were not taken at that time, 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, “possibly excessive.” But he told National TV on Monday that the guidelines for expert committees should be followed.

Reports also suggested that thousands of people were looking to leave the island. Nevertheless, Mr. Zorzos: “There is no mass immigration, some people choose to leave.”

Greek TV Monday showed dozens of cars waiting for Santorini’s most important port, while the Aegean airlines said it had added three additional flights from the island on Monday and Tuesday.

Mr. Zorzos had been because of Athens on Monday to open the island’s annual tourist campaign, an event that was canceled on Sunday night.

The impact of tourism on the island was unclear, though the British Foreign Office included the official warnings in its online Travel guidance For Greece.