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. According to old documents, the earth shook violently three times. The estimated rupture area for the earthquake is similar to that calculated for the
1933 Sanriku earthquake. 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. The damage from the tsunami far exceeded that from the earthquake, so this is considered to be a
tsunami earthquake. Consequently, the disaster caused by earthquake is also known as the "Keicho Sanriku tsunami earthquake". It would have been very similar to the
1605 Keichō Nankaidō earthquake, a tsunami earthquake in the
Nankai Trough area. ==Sources==