July 20, 1835 Tsunami: Sanriku, Japan
A tsunami caused by a magnitude 7.6 earthquake began at Sanriku, Japan on July 20, 1835. The water rose as high as 5 meters. Its effects were recorded at 4 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
- July 20, 1835
- Source
- Sanriku, Japan
- Cause
- Earthquake
- Earthquake
- Magnitude 7.6
- Maximum water height
- 5 m (16.4 ft)
- Runups recorded
- 4
- Tsunami intensity (Soloviev-Imamura)
- 2
- Tsunami magnitude (Iida)
- 2.3
- Waters
- Ocean
- How certain
- Definite tsunami
- Source location
- 37.900° N, 141.900° E
The toll
- Deaths
- Many (about 101 to 1,000)
- Damage
- Severe (about $5 to $25 million)
- Houses destroyed
- Many (101 to 1,000)
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:
uly 20, 1835 (37.9 N, 141.9 E, magnitude 7.6. There was a very strong earthquake and tsunami in Miyagi and Iwate Prefectures. A castle at Sendai was completely destroyed and 400-500 homes were flooded and washed away by the sea; many people died. One of the points where the tsunami occurred was Hanabuchi near Sendai (or Hanasaki on Hokkaido Island).
Reference #150:
July 20, 1835, 13-15 local time, 37.9 N, 141.9 E, magnitude 7.6, Off Miyagi Prefecture. Several hundred houses washed away. Many drowned. Sendai castle destroyed. Ryori 2.5 m, Takada 2m (Iwate Prefecture), Nobiru 5 m (Miyagi Prefecture).
Reference #79:
July 20, 1835, 14 local time, 37.9 N 141.9 E, magnitude 7.6. Japan, Rikuzen, Sendai area. Several hundred houses washed away. Many deaths. Imamura misprints Japanese year as Tenpo 5. Sieberg gives date of Aug. 19 for a quake at Mutsu (Aomori) and Hokkaido accompanied by a tsunami at Sendai, confusing report given here under 1835 Sept.--with report of Sendai event.
Reference #1897:
1835. Sea wave at Hanasaki.
Reference #3785:
1835, July 20, p. 90; 1825, July 20, p. 62.
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 |
|---|---|---|---|---|---|---|---|
| Nobiru | Japan | 83 | 5 | Eyewitness observation of water height | |||
| Sendai | Japan | 86 | Eyewitness observation of water height | ||||
| Ryori | Japan | 125 | 2.5 | Eyewitness observation of water height | |||
| Takada | Japan | 126 | 2 | Eyewitness observation of water height |
More
Every tsunami in 1835The 1800sTsunamis 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 691.