Santorini is the name of a small archipelago in the south of the Cyclades and on the main island, mostly in Greek Thira after transcription from ancient Greek and Thera is the Wild ‘called). Santorini was inhabited in 2001 by about 13,400 inhabitants. Since the administrative reform of 2010, it is known as Thira, while a church (Greek dimos) in the region of South Aegean.
The Santorini island group located in the southern Aegean Sea about 120 km north of Crete. The nearest islands are Anafi 22 km east and Ios 19 km north, Milos is located about 77 km north-west. The ring-shaped islands of Thira, Thirasia and Aspronisi form the edge of the sea flooded caldera in the center of the islands Palea Kameni and Nea Kameni lie. The entire archipelago has a diameter of about 16 km. The total area is approximately 92.5 km². Are due to the geological development of the Christiana islands and the underwater volcanic Kolumbos the Santorini archipelago.
From 150 to 350 m high caldera wall is the slope of Thira and Thirasia outwardly gentle. Only in the south east of Fira interrupts the Profitis Ilias mountain range , with 567 meters the highest point of the archipelago, these gentle drop. In many places, a wide black lava in transition to sea. In other places the Bimsdecke enough to the sea and forms then cliffs. In Thira, with the exception of Profitis Ilias mountain range and to characterize Thirasia deep gullies in the soft Bimsdecke caused by winter rains, the topography.
The maximum extent of the crescent-shaped main island of Thira is from Cape Mavropetra in the north to Cape Exomitis 17.4 km to the south. The width varies from 1.2 km in the north to about 6 km in the south. About 70% of the island is covered by some massive pumice. In the north, these layers of older volcanoes in the south of older Lavadomen interrupted. Each accounted for 15% lava and cinders, and the metamorphic basement rocks.
The caldera of Santorini covers an area of some 84.5 square kilometers, the extension is in north-south direction is about 11 km west-east direction almost 8 km. The absolute height of the north of Thira from the seabed about 700 meters. The caldera floor is composed of four sub-basins. The northeastern part of basin reaches a depth of nearly 400 meters and was probably formed by the processes of the Minoan eruption.