Lake Toba is the site of a massive supervolcanic eruption estimated at VEI 8 that occurred 69,000 to 77,000 years ago , representing a climate-changing event . Recent advances in dating methods suggest a more accurate identification of 74,000 years ago as the date . It is the largest-known explosive eruption on Earth in the last 25 million years . According to the Toba catastrophe theory , it had global consequences for human populations ; it killed most humans living at that time and is believed to have created a population bottleneck in central east Africa and India , which affects the genetic make-up of the human worldwide population to the present . It has been accepted that the eruption of Toba led to a volcanic winter with a worldwide decrease in temperature between , and up to in higher latitudes . Additional studies in Lake Malawi in East Africa show significant amounts of ash being deposited from the Toba eruptions , even at that great distance , but little indication of a significant climatic effect in East Africa
Toba catastrophe theory
Toba catastrophe theory
Lake Toba