The deadliest tsunami in Japanese history occurred on June 15th 1896, the tsunami killed more than 22,000 people. The tsunami was due to the Sanriku earthquake on the same day which was one of the most destructive seismic events in Japanese history, it was an 8.5 magnitude on the Richter scale. The earthquake occurred approximately 166 kilometres (103 mi) off the coast of Iwate Prefecture, Honshu.
On the evening of June 15, 1896, communities along the Sanriku coast in northern Japan were celebrating a Shinto holiday and the return of soldiers from the First Sino-Japanese War. After a small earthquake, there was little concern because it was so weak and many small tremors had also been felt in the previous few months. However 35 minutes later the first tsunami wave struck the coast, followed by a second a few minutes later. Damage was particularly severe because the tsunamis coincided with high tides. Most deaths occurred in Iwate and Miyagi although casualties were also recorded from Aomori and Hokkaido.
The waves reached a record height of 38.2 metres (125 ft); more than a meter lower than those created after the 2011 Tohoku earthquake which was much greater than expected for the estimated seismic magnitude. This earthquake is now regarded as being part of a distinct class of seismic events, the tsunami earthquake.