Toba catastrophe theory

The Youngest Toba eruption was a supervolcanic eruption that occurred around 75,000 years ago at the site of present-day Lake Toba in Sumatra, Indonesia. It is one of the Earth’s largest known explosive eruptions. The Toba catastrophe theory holds that this event caused a global volcanic winter of six to ten years and possibly a 1,000-year-long cooling episode.

About Toba catastrophe theory in brief

Summary Toba catastrophe theoryThe Youngest Toba eruption was a supervolcanic eruption that occurred around 75,000 years ago at the site of present-day Lake Toba in Sumatra, Indonesia. It is one of the Earth’s largest known explosive eruptions. The Toba catastrophe theory holds that this event caused a global volcanic winter of six to ten years and possibly a 1,000-year-long cooling episode. In 1993, science journalist Ann Gibbons posited that a population bottleneck occurred in human evolution about 70,000 Years ago, and she suggested that this was caused by the eruption. Both the link and global winter theories are controversial. The Youngest toba eruption is the most closely studied supervolcanoic eruption. It may have been responsible for a millennium of cool climate prior to the 19th Dansgaard-Oeschger event. The eruption did not precipitate the last glacial period. However, assuming an emission of six billion tons of sulphur dioxide, his computer simulations concluded that a maximum global cooling of approximately 15 °C occurred for three years after the eruption, and that this cooling last for decades.

Because the saturated adiabatic lapse rate is 4.000 m for the tree line and snow line were around 3,000 m at this time, no evidence has been found that the cold period from the eruption had resulted from the supercanic eruptions of Toba. Despite these different estimates, scientists agree that the eruption of a superVolcanic. eruption resulted in a drop of the global mean surface temperature by 3–5°C. Despite this, Clive Oppenheimer believes that estimates of a temperature drop of 3–4°C are probably too high, and he suggests that the temperature drop in surface temperature was probably only 1°C to 3°C by the end of the 20th century. This eruption was the last and largest of four eruptions during the Quaternary period. It had an estimated volcanic explosivity index of 8 ; it made a sizable contribution to the 100 × 35 km caldera complex.