Lake Toba
Lake Toba At least four cones, four stratovolcanoes, and three craters are visible in the lake. The Tandukbenua cone on the north-western edge of the caldera has only sparse vegetation, suggesting a young age of several hundred years. Also, the Pusubukit volcano (1971 meters above sea level) on the south edge of the caldera is solfatarically active and has stated as Geology Sanctuary. The Toba eruption occurred at what is now Lake Toba about 67,500 to 75,500 years ago. It was the last in a series of at least three caldera-forming eruptions at this location, with earlier calderas having formed around 700,000 and 840,000 years ago. This last eruption had an estimated VEI 8, making it possibly the largest explosive volcanic eruption within the last 25 million years. The subsequent collapse formed a caldera that, after filling with water, created Lake Toba . The island in the center of the lake is formed by a resurgent dome. Evidence from studies of mitochondrial DNA suggests that huma...