March 1747 Tsunami: Izu Peninsula, Hachijo Island, Japan
A tsunami of unknown cause began at Izu Peninsula, Hachijo Island, Japan in March 1747. 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
- March 1747
- Source
- Izu Peninsula, Hachijo Island, Japan
- Cause
- Unknown
- Runups recorded
- 2
- Tsunami intensity (Soloviev-Imamura)
- 0.5
- Tsunami magnitude (Iida)
- 0
- Waters
- Ocean
- How certain
- Questionable tsunami
- Source location
- 33.100° N, 139.800° 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.
Reference #414:
1747, March?. There were waves on the coast of the Izu Peninsula and Hachijo Island. Fishing boats were sunk or washed away on the coast of the Ogago region (Hachijo Island). No earthquake is reported. This was a tsunami from a remote source or of storm origin.
Reference #150:
1747. Hachijo island, validity 2, magnitude 1. Fishing boats washed away at Ogago [Hachijo Island]. No earthquake description.
Reference #79:
1747, March. Tsunami magnitude 0. Unknown source. Japan, Izu Island, Hachijo.
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 |
|---|---|---|---|---|---|---|---|
| Hachijo Island | Japan | 3 | Eyewitness observation of water height | ||||
| Izu Peninsula | Japan | 203 | Eyewitness observation of water height |
More
Every tsunami in 1747The 1700sTsunamis of JapanAlerts 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 427.