An earthquake measuring 4.8 on the Richter scale occurred shortly after 7 pm in the sea area off Kythnos, an island in the Western Cyclades between Kea and Serifos.

According to the revised solution of the Geodynamic Institute of Athens, the epicentre of the earthquake is located 39 kilometres west-southwest of Kythnos.

The focal depth of the earthquake is estimated at 114.7 kilometres.