01.23
It is 3,500 years ago and the long, lazy Aegean summer is drawing to its close. It is dusk and the rays of the dying sun pick out a tiny island so nearly a perfect circle in its outline, so compellingly lovely with its ochre-coloured volcano rising out of a violet sea, that even among the islands of the Aegean it is outstanding for its beauty.
The swallows streak through the sky, darting and wheeling in the blaze of the setting sun. The branches of the olive tress quiver in the light evening breeze.
The island’s harbour is quiet, now that the business of the day is over. The fisherman are going home with their shining, silvery catches. The narrow streets begin to fill with people , laughing and talking. In the doorways of the little houses women sit gossiping and from dozens of tiny workshops all over the town comes the cheerful whirr of the potter’s wheel. In the orchards and vineyards, the men are strolling home after the day’s labour.
The shadows lengthen as night comes. Then a strange choking heat engulfs the town. The sea turns to the colour of lead. From deep within the earth comes a muffled rumbling, intermittent at first but soon continuous.
Panic seizes the islanders. They sense that the great volcano, whose 1,500-metre peak dominates their lives, is about to erupt and that the god who controls the earth-shaking forces inside the volcano has awoken from his long sleep.
What they could not have known, as they stumbled from their houses clutching a few frantically snatched treasures, was that their town, their island and ultimately their whole civilisation was about to be destroyed by what, according to evidence gathered by volcanologists and seismologists of a later day, has come to rate as one of the most violent volcanic cataclysms the world has ever seen.
First came a choking plume of dark smoke. Then a terrible rain of blazing pumice stone, followed by ash, poured down in between explosions blasting up from the cone. At the height if the cataclysm, the volcano itself exploded under enormous internal pressures.
With a bang that was heard from one end of the mediterranean to the other and must have sounded like the end of the world, most of the island was blasted into dust.
Finally, the magma chamber beneath the volcano emptied, spewing out millions of tonnes of solid rock and, as a result, the great volcano collapsed in on itself, forming a steep-sided caldera or crater, 60 kilometres in circumference. Into this void poured the sea, bringing even more horrors in its wake.
These were the giant tsunamis, tidal waves which are set off by earthquakes or volcanic eruptions and are perhaps the most terrifying forces in nature. Waves as high as 200 metres radiated from the island to strike nearby coasts with a force that has never been equalled.
This is how scientists today see the sequence of events that the island 3,500 years ago. An explosion that they estimate produced a destructive force equivalent to 500-1000 atomic bombs.
A terrible darkness, caused by the thick fall of ash, descended on the Aegean, plunging the whole area into a night that was to last for weeks. The ash itself continued to fall for some time and today deposits of it, called tephra, lie more than 60 metres deep on what remains of the island which the Greeks call Kalliste.
Scientists now believe that what happened to Kalliste might be the solution to a riddle that has perplexed historians and geographers since the days of the Greek philosopher Plato (427-347 BC).