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Country: | Indonesia | |
| Subregion Name: | Sumatra (Indonesia) | ||
| Volcano Number: | 0601-09= | ||
| Volcano Type: | Caldera | ||
| Volcano Status: | Holocene | ||
| Last Known Eruption: | Unknown | ||
| Summit Elevation: | 2157 m | 7,077 feet | |
| Latitude: | 2.58°N | 2°35'0"N | |
| Longitude: | 98.83°E | 98°50'0"E | |
| The 35 x 100 km Toba caldera, the Earth's largest Quaternary caldera, was formed during four major Pleistocene ignimbrite-producing eruptions beginning at 1.2 million years ago. The latest of these produced the Young Toba Tuff (YTT) about 74,000 years ago. The YTT represents the world's largest known Quaternary eruption, ejecting about 2500-3000 cu km (dense rock equivalent) of ignimbrite and airfall ash from vents at the NW and SE ends of present-day Lake Toba. Resurgent doming forming the massive Samosir Island and Uluan Peninsula structural blocks postdated eruption of the YTT. Additional post-YTT eruptions include emplacement of a series of lava domes, growth of the solfatarically active Pusukbukit volcano on the south margin of the caldera, and formation of Tandukbenua volcano at the NW-most rim of the caldera. Lack of vegetation suggests that this volcano may be only a few hundred years old (Chesner and Rose, 1991). | |||
