The Meteorological Agency has introduced a quick tsunami warning system to help Okushiri islanders evacuate from their homes before tideal waves arrive. Okushiri island, a 143-square-kilometre island in the Sea of Japan off the western part of the Oshima Peninsula in Hokkaido, was the scene of a disaster caused by an earthquake and tsunami in the sea off soouthwestern Hokkaido in July 1993 that killed 198 islanders.