Santorini, one of the Cycladic islands, is a historically active volcano and part of the South Aegean (or Hellenic) volcanic arc in the Aegean Sea, located about 120 km north of Crete.
Santorini, or officially called Thira, consists actually of a group of islands:
– The main island Thera (75,8 km2, ca. 7000 inhabitants)
– Therasia (9,3 km2, ca. 250 inhabitants)
– Aspronisi (0,1 km2, uninhabited)
– Palea Kameni (0,5 km2, 1 inhabitant)
– Nea Kameni (3,4 km2, uninhabited)
Apart from a small non-volcanic basement represented in the south-eastern part of Thera these islands are composed of volcanic rocks from hundreds of eruptions during the last 2 million years, some of them being large caldera-forming events.
Palea and Nea Kameni formed during several lava eruptions in historic time within the caldera created by collapse of the magma chamber after the Minoan eruption. Nea Kameni is still active with the last eruption in 1950.