Lake Toba (Indonesian: Danau Toba)
is a lake and supervolcano. The lake is 100 kilometres long and 30
kilometres wide, and 505 metres (1,666 ft) at its deepest point. Located
in the middle of the northern part of the Indonesian island of Sumatra
with a surface elevation of about 900 metres (2,953 ft), the lake
stretches from 2.88°N 98.52°E to 2.35°N 99.1°E. It is the largest lake
in Indonesia and the largest volcanic lake in the world. Lake Toba is the site of a
supervolcanic eruption that occurred an estimated 69,000 to 77,000 years
ago, a massive, climate-changing event. It is estimated to have been a
VEI 8 eruption. It is the largest known explosive eruption anywhere on
Earth in the last 25 million years. According to the Toba catastrophe
theory, it had global consequences, killing most humans then alive and
creating a population bottleneck in Central Eastern Africa and India
that affected the genetic inheritance of all humans today. However, this
hypothesis is not widely accepted due to lack of evidence for any other
animal decline or extinction, even in environmentally sensitive
species. However, it has been accepted that the eruption of Toba led to a
volcanic winter with a worldwide decline in temperatures between 3 to 5
°C (5 to 9 °F), and up to 15 °C (27.0 °F) in higher latitudes.