Ontakesan

September 14, 1984 Eruption of Ontakesan

September 14, 1984 · 29 deaths

Ontakesan in Japan erupted on September 14, 1984. The eruption killed 29 people.

Where it erupted

Ontakesan, Japan, with its other significant eruptions.

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The eruption

Date
September 14, 1984
Volcano
Ontakesan, complex volcano
Country
Japan
Killed by
Avalanche (debris and landslides)
Location
35.893° N, 137.480° E

The toll

Deaths
29

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.

An earthquake caused the S flank of the volcano to collapse, creating a debris avalanche which killed 10 people in a hot spa. Some deaths may be from other landslides caused by quake. First historical eruption ended in April 1980, after 6 months. No eruption. (reference #9675)

Other significant eruptions of Ontakesan

More

Every eruption in 1984The 1900sOntakesanEarthquakes near OntakesanThis 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 6473.