August 23, 1856 Earthquake: Oshima, Japan
A magnitude 8 earthquake struck Oshima, Japan on August 23, 1856. It killed 26 people, counting the tsunami it caused.
Map
Where it struck, with the other significant earthquakes within 200 km. Circles are sized and colored by magnitude; select one for its page.
The earthquake
- Date
- August 23, 1856
- Place
- Oshima, Japan
- Magnitude
- 8 (Ms)
- Intensity
- 5 on the Modified Mercalli scale
- Tsunami
- Yes: the tsunami it caused
- Epicenter
- 40.500° N, 143.500° E
- Country
- Japan
The toll
- Deaths
- 26 with its tsunami and other effects
- Damage
- Moderate (about $1 to $5 million) with its tsunami and other effects
- Houses destroyed
- 193 with its tsunami and other effects
- Houses damaged
- 238 with its tsunami and other effects
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:
1856, Aug 23. Three strong shocks were registered at Hakodate, on Hokkaido Island, on August 19, and two shocks on August 20. On the 23rd at about 13:00 Local Time, there was a strong earthquake with a source probably at sea near Shiriya Cape. It was felt on the southern and eastern coasts of Hokkaido and on Sanriku. The intensity of tremors on the south of Hokkaido was [V MMI] (V JMA). On the west of the Tokachi region, the road running along the coast was blocked by falling rocks. There was no destruction, heavy damage to buildings, or victims. However a rather strong tsunmai was observed after the earthquake, and did considerable damage. The Komagatake volcano erupted three days after the earthquake.
Reference #150:
1856, Aug 23. 40.5 N, 143.5 E, 8. 26 drowned. 100 houses collapsed. 93 houses washed away.
Different Reports of Epicenters
LatitudeLongitudeMagnitudeReference #42N141.1E6.9#41440.5N143.5E7.8#150
Other significant earthquakes nearby
Within 200 km, the deadliest first.
- June 15, 1896, Sanriku, Japan
- December 2, 1611, Sanriku, Japan
- March 2, 1933, Sanriku, Japan
- December 6, 1616, Sanriku, Japan
- May 16, 1968, Off East Coast of Honshu Island, Japan
- March 4, 1952, Hokkaido, Japan
- August 9, 1901, Off Northeast Coast Honshu, Japan
- December 28, 1994, Honshu, Japan
- September 25, 2003, Hokkaido, Japan
- July 23, 2008, N, Honshu, Japan
- January 29, 1763, Sanriku,mutsu, Japan
- August 20, 2016, Off East Coast Honshu, Japan
- April 8, 1994, Off East Coast of Honshu Island, Japan
- February 20, 1979, Iwate, Japan
- June 10, 1088, Sanriku, Japan
More
Significant earthquakes of 1856The 1800sRecent earthquakes near hereThis day in weather history
Sources
Significant earthquakes 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 earthquake 2001.