Hellenic Volcanic Arc

The Hellenic arc is an arcuate mountain chain located on the southern margin of the Aegean Sea plate, resulting from the subduction of the African plate under it along the Hellenic subduction zone. It encroaches on mainland terrain in Greece, Turkey, and Crete, and is mainly marine, with mountaintops appearing as islands in the Ionian Sea and the Aegean. The subduction direction is northward, with locations on the arc or near it on the north side being called "outer" and those further north being "inner". The Hellenic arc and trench are moving in the reverse direction, from inner to outer, due to back-arc extension. The top layer of the subduction zone is moving from inner to outer, while the bottom layer is moving from outer to inner. The arc is composed of two layers, with the top layer being thinner and weaker due to back-arc extension. The Hellenic arc is one of the most active seismic zones in western Eurasia, with regular magnitude 7 earthquakes and at least two historical events of magnitude 8 or more.learn more on wikipedia