February 8, 1793 Tsunami: W. off Aomori, Japan

Reference #414:

On February 8 at 12:00 [local time] there was a very strong earthquake on the west of Aomori Prefecture. The source was apparently situated in the coastal region of Odose, and possibly also under the floor of the sea. The earthquake destroyed 164 homes and caused a small tsunami. Twelve people died in the earthquake and tsunami.

According to chronicles, some more or less marked changes in the relief of the earth's surface occurred in the area of the source before the earthquake. In the morning, it was noted that the sea had begun to retreat, and the ground was bulging in places. The residents of Ajigasawa took this as a sign of a tsunami and began to take to less dangerous places. However, the mountains and cliffs collapsed as a result of the shock. In panic, people fled from the landslides and rolling stones to the seaside. At that time, a tsunami wave approached the coast; there were victims. It is possible however, that all this is exaggerated. According to a later account of the effects of this earthquake, there were no victims of the earthquake at Ajigasawa.

Nanatsuishi (eastern part of the city of Ajigasawa) suffered comparatively heavily. A wave flooded and washed away homes and fishing boats. The settlement of Maido suffered still more greatly from the tsunami. There were victims here; the bridge spanning the river fell. The sea retreated from shore on the coast of Nishitsugaru district; children went onto the dried up part and drowned in the subsequent crest. In addition, the tsunami was strong at Kanaishawa. The water reached the foot of a large tree, growing at a height of 3.6 m above sea level. The depth of the flood reached 1.5-1.8 m here.

Probability 3.

Reference #150:

1793, Feb. 28, 40.85 N, 139.95 E, magnitude 6.9. 12 deaths. More than 175 houses destroyed. Land upheaved 3.5m at Otose, Ajigasawa, Aomori Pref. 23 boats damaged.