Lake Toba
| Lake Toba | |
|---|---|
| Danau Toba (Indonesian) | |
A view of Lake Toba and Samosir Island | |
Lake Toba Lake Toba | |
| Location | Balige, North Sumatra |
| Coordinates | 2°41′N 98°53′E / 2.68°N 98.88°E |
| Type | Volcanic/tectonic |
| Part of | Asahan Toba basin |
| Primary outflows | Asahan River |
| Basin countries | Indonesia |
| Max. length | 100 km (62 mi) |
| Max. width | 30 km (19 mi) |
| Surface area | 1,130 km2 (440 sq mi) |
| Average depth | 216 m (709 ft) |
| Max. depth | 505 m (1,657 ft) |
| Water volume | 244 km3 (59 cu mi) |
| Surface elevation | 905 m (2,969 ft) |
| Islands | Samosir (major) Hole, Sibandang, Tulas |
| Settlements | Ambarita, Pangururan |
| References | |
Lake Toba (Indonesian: Danau Toba, Toba Batak: ᯖᯀᯬ ᯖᯬᯅ; romanized: Tao Toba) is a large natural lake in North Sumatra, Indonesia, occupying the caldera of the Toba supervolcano. The lake is located in the middle of the northern part of the island of Sumatra, with a surface elevation of about 900 metres (2,953 ft), the lake stretches from 2°53′N 98°31′E / 2.88°N 98.52°E to 2°21′N 99°06′E / 2.35°N 99.1°E. The lake is about 100 kilometres (62 miles) long, 30 kilometres (19 mi) wide, and up to 505 metres (1,657 ft) deep. It is the largest lake in Indonesia and the largest volcanic lake in the world. Toba Caldera is one of twenty geoparks in Indonesia, and was recognised in July 2020 as one of the UNESCO Global Geoparks.
Lake Toba is the site of a 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 precise eruption date of 74,000 years ago. It is the largest-known explosive eruption on Earth in the last 25 million years.
A theory known as the Toba catastrophe theory postulates that this event held global consequences for Earth's human population. As the eruption likely would have killed most humans along with many other creatures living at the time, the theory suggests, it could account for an apparent population bottleneck in central east Africa and India around that time. A catastrophic loss of genetic diversity would affect the genetic make-up of humans worldwide, affecting human evolution to the present. More recent studies have cast doubt on this theory, as no evidence has emerged of lasting reductions in populations of humans and other fauna at the time. Other possibilities exist, including migration patterns, to account for apparent reductions in human genetic diversity.
It has also been suggested that the eruption of the Toba Caldera led to a volcanic winter with a worldwide decrease in temperature between 3 and 5 °C (5.4 and 9.0 °F), and up to 15 °C (27 °F) at higher latitudes. Additional studies in Lake Malawi in East Africa show significant amounts of ash deposits from the Toba Caldera eruptions even at that great distance, yet little indication of a significant climatic effect in East Africa.