The Toba supereruption
The largest eruption in two million years — and probably not the human catastrophe it was long claimed to be.
- When
- Known to
- ± 2 thousand years
- Era
- Late Pleistocene, Quaternary
About 74,000 years ago the Toba caldera in Sumatra erupts roughly 2,800 cubic kilometres of material, spreading ash across South Asia in a layer still traceable today. For decades a popular hypothesis held that the resulting volcanic winter reduced humanity to a few thousand individuals — the Toba bottleneck. That claim has largely collapsed: archaeological sequences in India and South Africa continue across the ash layer without interruption, climate models give a milder and briefer cooling than assumed, and the genetic bottleneck does not date to 74,000 years.