Toba catastrophe theory
The Toba eruption (sometimes called the Toba supereruption or the Youngest Toba eruption) was a supervolcano eruption that occurred around 74,000 years ago during the Late Pleistocene at the site of present-day Lake Toba in Sumatra, Indonesia. It is one of the largest known explosive eruptions in the Earth's history. The Toba catastrophe theory holds that this event caused a severe global volcanic winter of six to ten years and contributed to a 1,000-year-long cooling episode, leading to a genetic bottleneck in humans.
| Toba eruption theory | |
|---|---|
| Volcano | Toba Caldera Complex |
| Date | c. 74,000 years BP |
| End time | 9–14 days |
| Type | Ultra-Plinian |
| Location | Sumatra, Indonesia 2.6845°N 98.8756°E |
| VEI | 8 |
| Impact | Second-most recent supereruption; impact disputed |
| Deaths | (Potentially) almost all of humanity, leaving around 3,000–10,000 humans left on the planet |
Lake Toba is the resulting crater lake | |
A number of genetic studies have revealed that 50,000 years ago, the human ancestor population greatly expanded from only a few thousand individuals. Science journalist Ann Gibbons has posited that the low population size was caused by the Toba eruption. Geologist Michael R. Rampino of New York University and volcanologist Stephen Self of the University of Hawaiʻi at Mānoa have supported her suggestion. In 1998, the bottleneck theory was further developed by anthropologist Stanley H. Ambrose of the University of Illinois Urbana-Champaign. However, some physical evidence disputes the links with the millennium-long cold event and genetic bottleneck, and some consider the theory disproven.