October 9, 1257 Tsunami: Sagami Bay, Japan
A tsunami caused by a magnitude 7 earthquake began at Sagami Bay, Japan on October 9, 1257. Its effects were recorded at 3 places.
Where the waves reached
The source (white) and every runup with a place, colored by the water height recorded there. A ring is a runup NCEI marks doubtful.
- Under 1 m
- 1 to 3 m
- 3 to 10 m
- 10 to 30 m
- 30 m and more
- Height not recorded
The tsunami
- Date
- October 9, 1257
- Source
- Sagami Bay, Japan
- Cause
- Earthquake
- Earthquake
- Magnitude 7
- Runups recorded
- 3
- Tsunami intensity (Soloviev-Imamura)
- 1
- Tsunami magnitude (Iida)
- 1
- Waters
- Ocean
- How certain
- Definite tsunami
- Source location
- 35.200° N, 139.500° E
The toll
- Damage
- Limited (under about $1 million)
Where the literature gives no number, NCEI records a description on a scale of 1 to 4, printed here in its words. Damage is in millions of US dollars of the year of the event, not adjusted for inflation.
What the record says
NCEI’s account, from the sources it cites.
Temple and shrine at Kamakura damaged. Landslide, ground fissured. South Sagami and Kazusa damaged by earthquake. Tsunami in South Sagami. (reference #150)
1257, October 9. There was a strong earthquake in the southern part of Kanto, homes and temples were damaged. There was a tsunami on the coast of Sagami Bay. The earthquake is mentioned in a number of papers (Mallet, 1855; Neumann, 1878; Anon. (J), 1899 a,b; Omorl, 1919). A tsunami was observed at Kuji and Noda (Iwate Prefecture)
(Imamura, 1942, 1949; Takahasi, 1951; Yamaguti, 1954; Iida, 1956; Ponyavin, 1965; Katsumata, 1966; -Iida- et a,,196 7; Watanabe, 1968; Hatori et al., 1973). Iida (1956): 35.2 N., 140.9' E.; magnitude=7, m=l. (reference #414)
Every runup
Nearest the source first. Heights are above sea level at the time; a tide gauge reads half the wave’s full height.
| Where | Country | Km from source | Water height, m | Inland, m | Measured by | First wave, UTC | Deaths |
|---|---|---|---|---|---|---|---|
| Sagami Bay | Japan | 0 | Eyewitness observation of water height | ||||
| Noda | Japan | 582 | Eyewitness observation of water height | ||||
| Kuji | Japan | 590 | Eyewitness observation of water height |
More
Every tsunami in 1257The 1200sTsunamis of JapanThe earthquakeThis day in weather historyAlerts in force
Sources
Tsunami events and runups from NOAA’s National Centers for Environmental Information, Global Historical Hazard Database, cited as NCEI/WDS, doi:10.7289/V5PN93H7. Public domain. Read 2026-09-24. NCEI tsunami event 106.