ATHENS — The Greek island of Santorini is now nearly deserted and the people who have not evacuated woke up to earthquakes on Wednesday. Those followed an earthquake measuring 5.0 on the Richter scale that struck in the sea near the island of Amorgos the day before, as fears mounted of a much larger earthquake or worse destroying parts of Santorini.

A series of smaller earthquakes there in recent days has already sent residents fleeing in droves as panic set in across the island famous for its dramatic volcanic caldera.   

By late Tuesday, more than 10,000 people had fled, mainly via ferry or plane to Athens, and most of the island resembled a ghost town. 

Santorini was the site of a catastrophic volcanic eruption around 1600 B.C. that reshaped the island and destroyed much of the ancient Minoan civilization. The volcanic caldera is dormant but still active; however, seismologists have assured people that the current earthquakes are not expected to trigger volcanic activity. 

Nerves are rattled all the same. Hundreds of earthquakes with magnitudes between 3 and 4.9 have been registered since Saturday between Santorini and the nearby island of Amorgos. Although Greece is no stranger to earthquakes, seismic activity of such frequency and intensity without having been preceded by a major quake is highly unusual, seismologists say.

The fault line producing the earthquakes runs for about 75 miles, but so far only part of it, between the islands of Santorini and Amorgos, has been activated. The epicenters are beneath the seabed, which scientists say is good news, as quakes centered beneath land could potentially be more destructive.

But a large quake could also trigger a tsunami, so authorities have warned people to stay away from coastal areas and head inland if they feel a significant earthquake.

So far, there has been no significant damage and no injuries, although rock slides near beaches have occurred.

Anxiety about what will happen next is rising with the seismic phenomenon in full swing and experts predicting that it will last a long time. The fear is that something big is coming. 

The Seismology Laboratory of the National University of Athens says that  from June to February 1, over 2,500 earthquakes were recorded  in the volcanic complex of Santorini, as well as in the Santorini-Amorgos zone,  — and over 1,200 within three days.

In a statement, the lab said that “The picture presented by the seismic activity in the area between Santorini and Amorgos, with an increasing number of earthquakes with magnitudes greater than or equal to 4.0, although probably showing cluster characteristics , it is not excluded that it has characteristics of a pre-earthquake sequence.”

The statement continued, at the same time, from February 1 to February 3, 43 earthquakes with a magnitude greater than or equal to 4.0 occurred. The largest earthquakes occurred on February 3 and February 4 with a magnitude of 5.0.”

In recent days residents of the island, which is hugely popular with tourists, were making a beeline for the main ferry port and queuing for boats bound for Piraeus, the port of Athens. On Tuesday, the number and pace of departures were taking on the characteristics of a mass evacuation. 

The Greek airline Sky Express was even offering free one-way tickets out of the island for children up to 12 years old and teachers. 

Aegean, the flag carrier of Greece, has been operating continuous flights from Santorini to evacuate citizens who wish to do so. “In total, during the first two days, Monday and Tuesday, approximately 2,500 to 2,700 passengers will have been transported from Santorini to Athens on our flights,” the company said in a statement.

An magnitude 7.7 earthquake in 1956 caused widespread destruction in Santorini and triggered a tsunami, with 56 people killed in the calamity. 

At Athens, the country’s Climate Crisis and Civil Protection Ministry is on high alert even as the mayor of Santorini, Nikos Zorzos, has urged calm. In a statement he said that “An inter-ministerial committee was held, in which the methods and the preparedness we have for dealing with a potentially larger event were analyzed.” He added that “the fault is smaller than the Amorgos fault, which even if it ruptures will produce earthquakes of lesser force than the great one of 1956, and the meeting had to do with the preparation we have at the local level.”

Santorini, along with Mykonos, is a major driver of tourism revenue in Greece. It is too soon to tell what impact the recent seismic activity will have on summer travel bookings, but right now the picture does not look good. Images of thousands of people fleeing, including small children and elderly citizens, are already inundating Greek media.

The source of Santorini’s immense cliffs and great beauty has always been the destructive force of the volcano at its murky heart. 

Santorini’s main villages are built along the rim of the volcano’s caldera — producing the dramatic scenery of cascading whitewashed houses and sunset viewpoints that make the island popular for millions of tourists, but also raising concerns in the event of a major earthquake.

A noted Greek seismologist,Gerasimos Papadopoulos, recently said that the “possibility is open” that the quakes, which began on January 24 and only seem to be intensifying, could be followed by a major earthquake. 

That much is impossible to predict. On Tuesday a professor of applied geophysics and seismology at the University of Thessaloniki, Costas Papazachos, said that “There is no serious technology or approach to be able to predict what will happen from here on.”