The Toba volcanic system produced the enormous eruption linked to Lake Toba about 74,000 years ago.
The eruption, often called the Youngest Toba eruption, created a vast caldera in northern Sumatra, Indonesia. The depression later filled with water to form Lake Toba, one of the world’s largest volcanic lakes. Samosir Island occupies a substantial uplifted area within the lake and is part of the caldera system.
Toba released an estimated thousands of cubic kilometres of volcanic material, placing it among the largest known explosive eruptions of the Quaternary period. Ash from the event has been identified across parts of South Asia and the Indian Ocean region. Scientists continue to study how much the eruption affected global climate and human populations; the severity of a proposed human population bottleneck remains debated.
Toba is a caldera system, not simply a steep cone-shaped volcano. It is sometimes compared with Yellowstone, Taupō, and Long Valley because all are large caldera systems, but they formed in different geological settings.