August 23, 1741 Eruption of Oshima-Oshima
Oshima-Oshima in Japan erupted on August 23, 1741 with a Volcanic Explosivity Index of 4. The eruption killed 2,000 people, counting its secondary effects. It caused a tsunami.
Where it erupted
Oshima-Oshima, Japan, with its other significant eruptions.
The eruption
- Date
- August 23, 1741
- Volcano
- Oshima-Oshima, stratovolcano
- Country
- Japan
- Volcanic Explosivity Index
- 4, large (eruption column 10 to 25 km)
- Killed by
- Waves or tsunami; Seismic, or volcanic earthquake (tectonic earthquake deaths excluded)
- Tsunami
- Yes: the tsunami it caused
- Location
- 41.510° N, 139.367° E
The toll
- Deaths
- 2,000 with the tsunamis, mudflows and other effects it caused
- Damage
- Severe (about $5 to $25 million) with the tsunamis, mudflows and other effects it caused
- Houses destroyed
- 871 with the tsunamis, mudflows and other effects it caused
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.
The volcano first erupted on 23 Aug. Tsunami accompanied a second eruption on 29 Aug. 1467 killed on W coast of Oshima Peninsula, 729 houses washed away by tsunami following tectonic earthquake and debris avalanche from N flank of Nishiyama. 8 more people killed and 82 houses destroyed by tsunami on coast of N Honshu.
1741, August 23. 1475 deaths. 1467 killed on W coast of Oshima Peninsula, 729 houses washed away by tsunami following tectonic earthquake and debris avalanche from N flank of Nishi-yama. 8 more people killed and 82 houses destroyed by tsunami on coast of N Honshu. (reference #9675)
1,467 deaths (reference #12371)
August 29: Large tsunami induced by sector collapse occurred, killing 1,467 (Hokkaido/Tsugaru) and washing away or destroying 791 houses. 1,521 ships damaged. (reference #12936)
More
Every eruption in 1741The 1700sOshima-OshimaEarthquakes near Oshima-OshimaThis day in weather history
Sources
Volcanoes and significant eruptions 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. Volcano numbers are the Smithsonian Institution’s Global Volcanism Program’s. NCEI event 2673.