1645 BC Eruption of Aniakchak
Aniakchak in the United States erupted in 1645 BC with a Volcanic Explosivity Index of 6.
Where it erupted
Aniakchak, United States.
The eruption
- Date
- 1645 BC
- Volcano
- Aniakchak, caldera
- Country
- United States
- Volcanic Explosivity Index
- 6, paroxysmal (eruption column over 25 km)
- Location
- 56.880° N, 158.170° W
The toll
The record gives no deaths, injuries or damage for this eruption.
What the record says
NCEI’s account, from the sources it cites.
Modern Aniakchak caldera formed about 3,500 years ago during a violent, catastrophic eruption. During the caldera-forming eruption, draining of underground magma reservoirs caused an existing stratocone to collapse, thereby creating the deep crater that persists today. The enormous impact of this eruption is evident in thick blankets of coarse, pumice-rich debris deposited by pyroclastic flows that flowed in all directions from the volcano. Pyroclasic flows from this eruption could have generated a tsunami in Bristol Bay. The year of the eruption 1645 BC +/- 10 years is from Ref #2432.
More
Every eruption in 1645 BCThe 1600s BCAniakchakEarthquakes near Aniakchak
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 4645.