July 20, 766 Eruption of Aira

Name: July 20, 766 Eruption of Aira
Start: 0766-07-20
Location: Aira, Japan

July 20, 766 · VEI 3 · Deaths: many

Aira in Japan erupted on July 20, 766 with a Volcanic Explosivity Index of 3. It caused a tsunami.

Where it erupted

Aira, Japan, with its other significant eruptions.

Open the live map with volcanic ash advisories

The eruption

Date: July 20, 766
Volcano: Aira, stratovolcano
Country: Japan
Volcanic Explosivity Index: 3, moderate to large (eruption column 3 to 15 km)
Tsunami: Yes: the tsunami it caused
Earthquake: Yes: the earthquake with it
Location: 31.577° N, 130.659° E

The toll

Deaths: Many (about 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.

Many deaths.

Other significant eruptions of Aira

Every eruption in 766 The 700s Aira Earthquakes near Aira This 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 844.