The geological history of Santorini begins million years ago, at a time where Europe and Africa where still joined. At that time what is now known as the Aegean Sea, was a land accumulation, known as “Aegis”, which linked mainland Greece with Asia Minor and Crete. About 6 million years ago, and after a long series of geological upheavals, Aegis sank beneath the surface of the water, that rushed in to take its place. The mountain peaks of the old mainland remained protruding above the surface of the sea and are what today we refer to as the islands of the Aegean Sea. The position occupied today by Santorini had only two or three significant islets to show, which are still there today, included into the principal land. They are the mountains Prophet Elias, the rocks above the modern harbor at Athinios, and the remote rock that stands proudly on the east coast of the island at Monolithos.The eruption of the volcano led the greater part of the island to the bottom of the sea and created myths such as the sinking of Atlantis. Geological evidence indicates that the volcano first appeared around 80.000 years ago. Ash found on the seabed and originated from this eruption covered an area stretching from Chios to Italy, and from North Africa almost as far as Cyprus.
Apart from ashes, the crater expelled other heavier hot substances that poured out in liquid or semi-liquid form and shaped a cone. This cone gradually grew covering the surface of the sea and joined with the islets already there to form an approximately circular island with a diameter of 9 miles. It is not known how many centuries the island needed to assume its final form.
The second catastrophic eruption happened around 1600 BC, and as a result, the entire island’s life was destroyed. Beneath the center of Strongyle, the flow of lava created an enormous hollow dome that was the eventually unable to support the weight of the island. The roof of the dome collapsed and the greater part of Strongyle sank beneath the waves. All that was left above the surface of the sea were parts of its perimeter that enclosed a gigantic basin filled with the sea – the Caldera. These parts are called today Santorini and Thirasia islands. The time of the submerge, Aegean Sea was darkened by an immense black cloud of smoke and ash and an enormous tsunami of 250m height, rose up an went in all directions. With the speed it is estimated that traveled, in approximately half an hour it had reached Crete and (as many historians believe), whipped out the Minoan civilization.
From time to time various craters erupted in the caldera, though unimportant, yet restarted the process of filling the caldera. The lava shaped cones around the crater, at first under sea and later projected above the surface and formed the two islands of Palaia Kammeni and Nea Kammeni, today called the Volcano. There were 14 eruptions ever since 198 BC. In 1707, once more, activity began in the center of the caldera. These chain events formed the island that can be seen today. In 1956 an earthquake destroyed everything on the island, so the island was rebuilt. Since 1956 volcanic activity has been pretty low, but minor tremors are quite common and the ground shakes, usually imperceptibly, almost every day. A major earthquake is due at any moment, but the locals don’t seem worried – they seem to like living on the edge.
So if you are a lover of impermanence, precariousness and drama, no other place comes close. Come see the hot springs of the caldera and the volcano’s crater (a unique experience) and you remember it for a lifetime.
Useful links
Volcano cruise Volcano Sunset cruise
