South Aegean Volcanic Arc
The Cycladic arc is a volcanic island arc in the southern Aegean Sea. It is about 450 km long and 20 km to 40 km wide and extends from the Isthmus of Corinth to Asia Minor Bodrum Peninsula. In this zone there are the Greek volcanoes Methana, Milos, Santorini and Nisyros.
In a zone south of Crete ( deep ditch ), the African plate pushes with currently 5 cm per year under the Aegean plate, a plate portion of the Eurasian Plate. At depths of about 150 to 180 km, the mantle rock is melted above the plate pushed under by escaping from those volatiles ( carbon dioxide crystal lattice water, halogens ). By then dissolved gases in the melt gets the molten rock buoyancy and rises in an arc- shaped zone about 120 km north of Crete in the form of volcanoes back to the surface (volcanic products: andesites, dacites, rhyolites ).