Wednesday, 11 May 2011
Santorini ,officially Thera are islands that are the remnants of a volcanic caldera located in the southern Aegean Sea, about 200 km southeast from Greece's mainland. It is the largest island of a small, circular archipelago which bears the same name. The municipality of Santorini is composed of the islands of Santorini, Therasia, and the uninhabited islands of Nea Kameni, Palaia Kameni, Aspronisi, and Christiana.
Santorini is essentially what remains of an enormous volcanic explosion, destroying the earliest settlements on what was formerly a single island, and leading to the creation of the current geological caldera. The island slopes downward from the cliffs to the surrounding Aegean Sea. On the fourth side, the lagoon is separated from the sea by another much smaller island called Therasia; the lagoon merges with the sea in two places, in the northwest and southwest. The water in the centre of the lagoon is nearly 400 m deep, thus making it a safe harbour for all kinds of shipping.
It is the most active volcanic centre in the South Aegean Volcanic Arc, though what remains today is chiefly a water-filled caldera. The region first became volcanically active around 3–4 million years ago though volcanism on Thera began around 2 million years ago with the extrusion of dacitic lavas from vents around the region of Akrotiri.
The island is the site of one of the largest volcanic eruptions in recorded history: the Minoan eruption , which occurred some 3,600 years ago at the height of the Minoan civilization. The eruption left a large caldera surrounded by volcanic ash deposits hundreds of feet deep and may have led indirectly to the collapse of the Minoan civilization on the island of Crete, 110 km to the south, through the creation of a gigantic tsunami. This theory is not, however, supported by chronology, in that the collapse of the Minoan civilization did not occur concurrently with the date of the tsunami; that happened some 90 years later.Another popular theory holds that the Thera eruption is the source of the legend of Atlantis.