Japan Sea Central Region Tsunami of May 26, 1983

A few seconds after noon on May 26, 1983, a major earthquake occurred in the Japan Sea about 100 km off the coast of Akita Prefecture, which is located in the northeast Honshu, Japan. The earthquake had a magnitude of 7.7 on the Richter scale, as measured by the Japan Meteorological Agency (JMA). Four individuals lost their lives directly from the earthquake, and considerable property damage occurred, primarily from foundation failure as a result of soil liquefaction.

The earthquake generated a tsunami that began striking the Japan coast approximately 12 minutes after the earthquake occurred. One hundred lives were lost as a consequence of the tsunami alone. The tsunami also caused significant flooding and property damage to coastal regions.The tsunami affected the entire Japan Sea, hitting the surrounding coastline of the Korean Peninsula and the USSR. Three lives were lost in South Korea, when the wave arrived there approximately 1-1/2 hours after the earthquake. At the time of this writing, no information is available on the impact of the tsunami in North Korea or the USSR.

The Japan Sea Central Region Tsunami focuses on the tsunami generated by the Japan Sea central region earthquake, as officially named by the JMA. The data presented herein were collected by the authors during site visits to Japan and South Korea approximately six weeks after the earthquake. Even though the recently acquired data are more reliable than those reported immediately after the earthquake, they must still be considered preliminary and subject to change as continuing studies in Japan are completed.