The 1993 Hokkaido earthquake tsunami devastated which small Japanese island?

The 1993 Hokkaido earthquake tsunami devastated Okushiri Island.

The magnitude 7.7 earthquake struck beneath the Sea of Japan on 12 July 1993, southwest of Hokkaido. Its tsunami reached Okushiri only about two to seven minutes after the shaking, leaving residents very little time to escape. The island was the hardest-hit location, suffering deaths from the tsunami, earthquake damage and a major landslide.

A maximum tsunami run-up of about 32 metres was recorded near Monai on the island’s western side. The waves also affected northern Honshu, southeastern Russia and South Korea, showing that a tsunami can cross an entire marginal sea rather than harming only the nearest shoreline.

Okushiri is sometimes confused with Hokkaido itself, Japan’s large northern island. Okushiri is a separate smaller island off Hokkaido’s southwest coast. The disaster prompted stronger sea defences, improved evacuation routes and wider use of emergency broadcast receivers.