Тоба (күл): юрамалар арасында аерма

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Smaller eruptions have occurred at Toba since. The small cone of [[Pusukbukit]] has formed on the southwestern margin of the caldera and lava domes. The most recent eruption may have been at [[Tandukbenua]] on the northwestern caldera edge, since the present lack of vegetation could be due to an eruption within the last few hundred years.<ref>{{Cite web|url=http://www.volcanodiscovery.com/volcano-tours/volcanoes/indonesia/sumatra/toba/|title=Toba volcano (Indonesia, Sumatra)|publisher=VolcanoDiscovery.com}}</ref>
 
Some parts of the caldera have experienced uplift due to partial refilling of the [[magma chamber]], for example pushing [[Samosir|Samosir Island]] and the [[Uluan Peninsula]] above the surface of the lake. The lake sediments on Samosir Island show that it has been uplifted by at least {{convert|450|m|0|abbr=on}}<ref name=OregonState/> since the cataclysmic eruption. Such uplifts are common in very large calderas, apparently due to the upward pressure of unerupted [[magma]]. Toba is probably the largest resurgent caldera on Earth. Large [[earthquake]]s have occurred in the vicinity of the volcano more recently, notably in 1987 along the southern shore of the lake at a depth of {{convert|11|km|abbr=on}}.<ref>{{cite web|url=http://earthquake.usgs.gov/eqcenter/eqarchives/significant/sig_1987.php|title=Significant Earthquakes of the World|publisher=[[United States Geological Survey]] (USGS)}}<!-- Bot generated title --></ref> Other earthquakes have occurred in the area in 1892, 1916, and 1920–1922.<ref name=OregonState>{{Cite web|url=http://volcano.oregonstate.edu/vwdocs/volc_images/southeast_asia/indonesia/toba.html|title=Toba, Sumatra, Indonesia|publisher=[[Oregon State University]]}}<!-- Bot generated title -->]</ref>
 
Lake Toba lies near the [[Great Sumatran fault]] which runs along the centre of Sumatra in the [[Great Sumatran fault|Sumatra Fracture Zone]].<ref name=OregonState/> The volcanoes of Sumatra and Java are part of the [[Sunda Arc]], a result of the northeasterly movement of the [[Indo-Australian Plate]] which is sliding under the eastward-moving [[Eurasian Plate]]. The [[subduction zone]] in this area is very active: the seabed near the west coast of Sumatra has had several major earthquakes since 1995, including the 9.1 [[2004 Indian Ocean Earthquake]] and the 8.7 [[2005 Sumatra earthquake]], the epicenters of which were around {{convert|300|km|abbr=on}} from Toba.