Sanriku Earthquake and Tsunami – Japan – June 15, 1896

This disaster included a powerful earthquake of magnitude 8.5, followed by a massive tsunami. It struck the northeast coast of Japan. There was little awareness of the earthquake because of its distance from shore and because of its character, but the tsunami that ensued was massive and did overwhelming damage on shore and killed 26,000 people.

On June 15, 1896, an earthquake of magnitude 8.5 struck the Sanriku coast on the northeast of Honshu, Japan, in the Iwate Prefecture. Its epicenter was ninety miles offshore, near an area of very deep water known as the Japan Trench. The impact on shore was much weaker than would normally be expected from such a powerful earthquake so there was little expectation of a tsunami, even though this part of the Japanese coast experiences earthquakes frequently. Thirty-five minutes after the earthquake, the most devastating tsunami in Japan’s history reached the shore at the same time as high tide. The first wave receded back out to sea and returned in a second wave five minutes later. At times the tsunami’s wave reached a height of 125 feet. Everything in its path was totally devastated. Twenty-six thousand people were killed and nine thousand homes destroyed. Its epicenter on a reverse fault near the Japan Trench was the reason for the mild impact felt on shore. The earthquake lasted for five minutes and was accompanied by a slow shaking.

Many villagers were at the beach celebrating two events when the earthquake occurred: the return of soldiers from a successful war with China, the first Sino-Japanese War of 1894, and the annual Boys’ Festival. Villagers observed minor shocks in the earlier part of the day, many hours before the earthquake. There were also reports of unusual phenomenon on that same day—low water levels in wells and large numbers of tunas every day. The violence of the tsunami was yet another unusual feature of the day. Usually victims in tsunami disasters die by drowning but, in the Sanriku tsunami, there was extensive damage to the bodies of victims; fractured skulls, bodies heavily scarred, and legs and arms broken. The impact of this tsunami carried across the Pacific. In Hawaii, wharves were demolished and several houses swept away. In California a 9.5 foot-high wave arrived. Unfortunately, in spite of the long history of tsunamis on this coast, very little beyond immediate humanitarian assistance was done by public authorities.

On June 16, the day following the tsunami disaster, a telegram reporting the disaster reached the Interior Ministry. After reporting to the Meiji emperor, the minister of the Interior Ministry contacted all ministries to deliver relief and rescue for the tsunami victims. The emperor delegated one person to visit the disaster site and cheer up the survivors with encouraging words. The governmental agencies dispatched inspectors and the army sent medical specialists. The military authorities also sent soldiers to secure public order, military engineers to recover bodies from the rubble, and the navy to search the water for bodies of the victims. The Japanese Red Cross Society and the Nurse Association sent doctors and nurses to treat the injured. However, it took a further thirty years before action was taken on detailed preventive measures.

In 1937, another very strong tsunami hit the coast of Sanriku. This time the local authorities were better prepared for it. They had installed tidal embankments, trees, and escape roads. They also prepared a booklet on precautions for preventing a disaster. This booklet included a warning about weak earthquake shocks, the kind of event that was so much misunderstood in 1896. At the same time it pointed out that a loud noise like thunder might indicate an approaching tsunami. Other things listed in the booklet included avoiding the recession of the tsunami’s first wave and being prepared to evacuate the coast quickly and move to higher ground.