Editing Lake Toba (section)

==Geology==
[[File:Lake Toba, North Sumatra (71).JPG|thumb|Batu Gantung (Hanging stone) in Lake Toba]]
[[File:Map of Lake Toba.jpg|thumb|Map of the lake]]
The Toba [[Caldera]] in [[North Sumatra]] comprises four overlapping volcanic craters that adjoin the Sumatran "volcanic front". At {{convert|100|by|30|km}} it is the world's largest [[Quaternary]] caldera, and the fourth and youngest caldera. It intersects the three older calderas. An estimated {{cvt|2800|km3}} of [[dense-rock equivalent]] pyroclastic material, known as the youngest Toba [[tuff]], was released during one of the largest explosive volcanic eruptions in recent geological history.<ref>{{Cite journal|last1=Budd|first1=David A.|last2=Troll|first2=Valentin R.|last3=Deegan|first3=Frances M.|last4=Jolis|first4=Ester M.|last5=Smith|first5=Victoria C.|last6=Whitehouse|first6=Martin J.|last7=Harris|first7=Chris|last8=Freda|first8=Carmela|last9=Hilton|first9=David R.|last10=Halldórsson|first10=Sæmundur A.|last11=Bindeman|first11=Ilya N.|date=25 January 2017|title=Magma reservoir dynamics at Toba caldera, Indonesia, recorded by oxygen isotope zoning in quartz|journal=Scientific Reports|language=en|volume=7|issue=1|pages=40624|doi=10.1038/srep40624|pmid=28120860|pmc=5264179|bibcode=2017NatSR...740624B|issn=2045-2322}}</ref> Following this eruption, a resurgent dome formed within the new caldera, joining two half-domes separated by a longitudinal [[graben]].<ref name=chesner1991>{{Cite journal|url= http://www.geo.mtu.edu/~raman/papers/ChesnerGeology.pdf |author1=Chesner, C.A. |author2=Westgate, J.A. |author3=Rose, W.I. |author4=Drake, R. |author5=Deino, A. |journal=Geology |volume=19 |issue=3 |pages=200–203 |title=Eruptive history of Earth's largest Quaternary caldera (Toba, Indonesia) clarified |publisher=Michigan Technological University |date=1991 |access-date=23 August 2008 |bibcode=1991Geo....19..200C |doi=10.1130/0091-7613(1991)019<0200:EHOESL>2.3.CO;2}}</ref>

At least four cones, four [[stratovolcano]]es, and three craters are visible in the lake. The Tandukbenua cone on the northwestern edge of the caldera has only sparse vegetation, suggesting a young age of several hundred years. Also, the Pusubukit (Hill Center) volcano ({{cvt|1971|m}} above sea level) on the south edge of the caldera is [[solfatara|solfatarically]] active.<ref>{{cite gvp|name=Toba: Synonyms & Subfeatures|vtab=Subfeatures|vn=261090|access-date=24 June 2021}}</ref>