
Toba Lake 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). It is the largest lake in Indonesia and the largest volcanic lake in the world. Toba Lake is the site of a supervolcanic eruption that occurred 69,000-77,000 years ago,a massive climate-changing event. The eruption is believed to have had a VEI intensity of 8. It is believed to be the largest explosive eruption anywhere on Earth in the last 25 million years.
According to the Toba catastrophe theory to which some anthropologists and archeologists subscribe, 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. This theory however, has been largely debated as there is no 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.
The Toba eruption (the Toba event) occurred at what is now Toba Lake about 67,500 to 75,500 years ago. The Toba eruption was the latest of a series of at least three caldera-forming eruptions which have occurred at the volcano, with earlier calderas having formed around 700,000 and 840,000 years ago.The last eruption had an estimated Volcanic Explosivity Index of 8 (described as "mega-colossal"), making it possibly the largest explosive volcanic eruption within the last 25 million years.
0 comments:
Post a Comment