The 1993 southwest-off Hokkaido earthquake or Okushiri earthquake occurred at 13:17:12 UTC on 12 July 1993 in the Sea of Japan near the island of Hokkaido. It had a magnitude of 7.7 on the moment magnitude scale and a maximum felt intensity of VIII (Severe) on the Mercalli intensity scale. It triggered a major tsunami that caused deaths on Hokkaidō and in southeastern Russia, with a total of 230 fatalities recorded. The island of Okushiri was hardest hit, with 165 casualties from the earthquake, the tsunami and a large landslide.

The 1983 Sea of Japan earthquake occurred on May 26, 1983 at 11:59:57 local time. It had a magnitude of 7.8 on the moment magnitude scale. It occurred in the Sea of Japan, about 100 km west of the coast of Noshiro in Akita Prefecture, Japan. Out of the 104 fatalities, all but four were killed by the resulting tsunami, which struck communities along the coast, especially Aomori and Akita Prefectures and the east coast of Noto Peninsula. Images of the tsunami hitting the fishing harbor of Wajima on Noto Peninsula were broadcast on TV. The waves exceeded 10 meters (33 ft) in some areas. Three of the fatalities were along the east coast of South Korea. The tsunami also hit Okushiri Island, the site of a more deadly tsunami 10 years later.