August 2, 704 Tsunami: Kumanonada, Japan
A tsunami caused by a magnitude 7 earthquake began at Kumanonada, Japan on August 2, 704. Its effects were recorded at 1 place.
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
- August 2, 704
- Source
- Kumanonada, Japan
- Cause
- Earthquake
- Earthquake
- Magnitude 7
- Runups recorded
- 1
- Tsunami intensity (Soloviev-Imamura)
- 2
- Tsunami magnitude (Iida)
- 2
- Waters
- Ocean
- How certain
- Definite tsunami
- Source location
- 33.800° N, 136.700° E
The toll
The record gives no deaths, injuries or damage for this tsunami.
What the record says
NCEI’s account, from the sources it cites.
Moderate tsunami reported at various inlets of Kumano. (reference #150)
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 |
|---|---|---|---|---|---|---|---|
| Kumamonada | Japan | Eyewitness observation of water height |
More
Every tsunami in 704The 700sTsunamis 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 55.