[4] At about 10:30 on December 2, 1611 (Keichō 16, 10th month, 28th day), there was a severe earthquake, and at about 14:00 (local time), this was followed by a devastating tsunami.

[5] The earthquake struck an area along the Pacific Ocean known as the Sanriku Coast, where the shaking intensity was 4–5 on the Shindo scale.

However, due to the time delay of nearly four hours before the tsunami arrived, there are questions about the exact location of the source.

It is possible that the earthquake and tsunami in Sanriku was an enormous quake that resonated even in the area of the Kurile Trench off the eastern coast of Hokkaido.

[6] The tsunami reached its maximum estimated height of about 20 metres (66 ft) at Ōfunato, Iwate.