Where it is and what it carries
The Aegean Sea Plate is a microplate covering most of the Aegean Sea, Crete, the Peloponnese and much of southern mainland Greece. In the dataset, 38% of Greece and about 3% of Turkey lie on it. Its crust is continental but stretched thin, which is why much of the region lies under shallow sea dotted with islands.
Geologists separate it because GPS shows the southern Aegean moving southwest as a coherent block, faster than both Eurasia and Anatolia. Its exact boundaries are less certain on land, where deformation spreads across many faults, and some models merge it with the Anatolian Plate.
What happens at its edges
The southern edge is the Hellenic Trench, a subduction zone about 1,070 km long where the African Plate sinks beneath the plate. Relative motion there is about 3.8 cm/yr, the fastest of the plate’s boundaries. Crete and the islands of the Hellenic Arc rise above the trench, and farther north the sinking slab reaches deep enough to feed a line of volcanoes.
To the north, the boundary with the Eurasian Plate runs through the Gulf of Corinth rift and the North Aegean Trough, with relative motion of about 3.0 cm/yr in PB2002. To the east, the plate pulls away from Anatolia at about 1.5 cm/yr, and that stretching opens the basins and grabens of western Turkey.
As the African slab sinks, it rolls back to the south. That pulls the Aegean crust with it and stretches it, a process called back-arc extension.
Volcanoes
The dataset lists 5 volcanoes on the plate, all part of the South Aegean Volcanic Arc: Methana, Milos, Santorini, Kolumbo and Nisyros. Santorini’s Bronze Age eruption was one of the largest of the past few thousand years and left the ring of islands around today’s caldera. Kolumbo, a submarine volcano northeast of Santorini, erupted in 1650.
Earthquakes
The plate has had 27 earthquakes of magnitude 6.5 or larger since 1900. The largest, a M7.9 in 1903 off southern Greece, struck about 80 km deep inside the sinking slab. The 1956 Amorgos earthquake (M7.7) was the largest shallow event, centered southeast of Amorgos in the Cyclades. Other large quakes hit near Koroni in the Peloponnese in 1947 (M7.3) and near Karpathos in 1948 (M7.3). In the north, a M7.2 struck west of Lesbos in 1981, and in 2020 a M7.0 off Samos damaged buildings in Samos and in Izmir, Turkey.