February 17, 1793 Tsunami: Sanriku, Japan
A tsunami caused by a magnitude 8.3 earthquake began at Sanriku, Japan on February 17, 1793. The water rose as high as 4.5 meters. Its effects were recorded at 8 places. It killed 745 people, counting the earthquake or eruption that caused it.
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
- February 17, 1793
- Source
- Sanriku, Japan
- Cause
- Earthquake
- Earthquake
- Magnitude 8.3, 33 km deep
- Maximum water height
- 4.5 m (14.8 ft)
- Runups recorded
- 8
- Tsunami intensity (Soloviev-Imamura)
- 2
- Tsunami magnitude (Iida)
- 2.2
- Waters
- Ocean
- How certain
- Definite tsunami
- Source location
- 38.500° N, 144.000° E
The toll
- Deaths
- 720; 745 with the earthquake or eruption that caused it
- Damage
- Severe (about $5 to $25 million)
- Houses destroyed
- 100; 1,160 with the earthquake or eruption that caused it
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:
1793, Feb. 2. There was an earthquake at Sanriku, which caused catastrophic tsunami waves on the coast of Iwate and Miyagi Prefectures (at Ozuchi, Ryoishi, Kamaishi, Ofunato, Kesennuma, Okachi and other places). One hundred homes were washed away and 720 residents died in Iwate Prefecture, including 17 homes washed away and 12 or 13 people killed at Ozuchi. The height of the wave was 3 m at Ofunato, and apparently 0.6 m at Okachi.
Reference #150:
1793, Feb 17. 38.5 N, 144 E, magnitude 8.25. 25 deaths, more than 1,060 houses damaged in Sendai area. Tsunami along the coast of Iwate and Miyagi Pref. Hachinohe 1.5m, Yamada 3.5m, Ootsuchi 2.5m, Ryoishi 4.5m, Ofunato 3m, Okachi 2.5m.
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 |
|---|---|---|---|---|---|---|---|
| Ryoishi | Japan | 203 | 4.5 | Eyewitness observation of water height | |||
| Kamaishi | Japan | 203 | Eyewitness observation of water height | ||||
| Ofunato | Japan | 204 | 3 | Eyewitness observation of water height | |||
| Otsuchi | Japan | 204 | 2.5 | Eyewitness observation of water height | 13 | ||
| Yamada | Japan | 208 | 3.5 | Eyewitness observation of water height | |||
| Kesennuma | Japan | 216 | Eyewitness observation of water height | ||||
| Okachi | Japan | 221 | 2.5 | Eyewitness observation of water height | |||
| Hachinohe | Japan | 310 | Eyewitness observation of water height |
More
Every tsunami in 1793The 1700sTsunamis 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 573.