- An earthquake of 6.8 M at the depth of 14 km occurred in the Ionian Sea (western Greece) on 25 October at 22:54 UTC. The epicentre was located offshore 45 km south-west of Zakintos Island. The earthquake affected the island of Zakynthos, but it was also felt in large part of Greece, southern Italy and northern Africa.
- A minor tsunami was measured in several locations in the area; the highest measured value was 11 cm in Kyparissia and 8 cm in Le Castella.
- Two NEAM Regional Tsunami Watch Centres (RTWCs), NOA (Tsunami Service Provider from Greece) and INGV (Tsunami Service Provider from Italy), timely issued international tsunami messages and lifted the alert 1h 47min and 4h 48min after the earthquake event.