Earthquakes in Greece

Greece's extraordinary seismicity is driven primarily by the Hellenic Arc — one of the fastest-moving subduction zones in the Mediterranean. The African plate subducts beneath the Aegean microplate (a small separate plate that includes most of Greece and the Aegean Sea) at approximately 4 cm per year. The resulting seismic activity spans from the Ionian Sea in the west, through Crete and the sea south of it, to Rhodes and the eastern Aegean.

The Ionian Islands — Corfu, Kefalonia, Zakynthos, and Lefkada — sit on the western boundary of the Aegean microplate and experience some of the highest seismicity in Europe. The 1953 Cephalonia earthquakes (M7.2 and M6.9) virtually destroyed the islands. More recently, the 2015 Lefkada earthquake (M6.5) and multiple Zakynthos events have repeatedly struck this region.

The Aegean extensional province is another major source of seismicity. As the Hellenic Arc retreats southward and the Aegean microplate moves southwestward relative to Eurasia, the northern Aegean Sea and northern mainland Greece experience extensional tectonics — with normal faults similar to those in the Apennines. The 1999 Athens earthquake (M5.9) occurred on a previously unknown normal fault near the suburb of Ano Liosia, killing 143 people and demonstrating that even moderate events can be catastrophic in populated areas.

The North Aegean Trough is a major E-W trending right-lateral fault system running from the Gulf of Athermal north of Athens eastward through the northern Aegean to the Anatolian fault system in Turkey. The 2014 North Aegean earthquake (M6.9) occurred on this system.

The magnitude 7.0 earthquake that struck off the coast of Samos in 2020 — also felt strongly in İzmir, Turkey — illustrated how major events can occur at the boundary between the Greek and Turkish fault systems. The resulting tsunami killed two people on Samos and the earthquake killed over 100 in İzmir.

Greece operates a national seismic monitoring network through the Geodynamic Institute of the National Observatory of Athens and the University of Athens Seismological Laboratory. The Earthquake Planning and Protection Organization (OASP) coordinates preparedness and response.