May 22, 1241 Tsunami: Kamakura, Sagami Bay, Japan
A tsunami caused by a magnitude 7 earthquake began at Kamakura, Sagami Bay, Japan on May 22, 1241. Its effects were recorded at 2 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
- May 22, 1241
- Source
- Kamakura, Sagami Bay, Japan
- Cause
- Earthquake
- Earthquake
- Magnitude 7
- Runups recorded
- 2
- Tsunami intensity (Soloviev-Imamura)
- 1
- Tsunami magnitude (Iida)
- 1
- Waters
- Ocean
- How certain
- Definite tsunami
- Source location
- 35.200° N, 139.400° 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.
May 22, 1241, 35.2 N, 139.4 E, Kamakura, Sagami Bay, magnitude 7. Shrine Hachiman at Yuiga-hama swept away. More than 10 vessels wrecked. (reference #150)
May 22, 1241 (erroneously 1240). 35.3 N, 139.3 E, magnitude 7. There was a large earthquake on the south of Kanagawa Prefecture. It was felt strongly at Kamakura. It was accompanied by a tsunami on the coast at Kamakura. In particular, a sea wave destroyed part of the Hachiman Shinto temple on the Yuigahama coast. More than ten ships were damaged. (reference #414)
May 22, 1241, 35.2 N, 139.3 E, magnitude 7. Source: Tokaido, Sagami Bay; Observation: Japan, Sagami, Tokaido, Kamakura, Yuigahama. Tsunami swept shrine. More than 10 boats wrecked. Year given incorrectly as 1240 by Sekiya and Omori (1904), Heck (1947), and Honda, a.o., (1908). (reference #79)
May 22, 1240. Japan, coast of Kamakura, province of Sagami. (reference #132)
May 22, 1240. Sea waves on the coast of Kamakura in the
province of Sagami. (reference #1897)
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 |
|---|---|---|---|---|---|---|---|
| Kamakura | Japan | 18 | Eyewitness observation of water height | ||||
| Yuigahama | Japan | 18 | Eyewitness observation of water height |
More
Every tsunami in 1241The 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 104.