How does a caldera form?
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2
3
4
http://www.bbc.co.uk/schools/gcsebitesize/geography/natural_hazards/volcanoes_rev4.shtml
What happens after a volcano erupts?
http://www.virtualuppermantle.info/Toba-Caldera.htm
http://earthobservatory.nasa.gov/IOTD/view.php?id=7380
Introduction
- 75, 000 years ago
- Indonesian Islands of Sumatra
Immediate Destruction
- Destroyed all life in immediate surroundings
- Hot flows
- Gas release
Comparison of the Toba
eruption to other
supervolcanic eruptions
What is a super-volcano?
A volcano capable of producing ejecta that is greater than 1000km3.
Volcanic Explosivity Index
- The Quaternary Epoch
- Noted as an 8
http://www.geolsoc.org.uk/ks3/gsl/education/resources/rockcycle/page3531.html
Genetic Bottleneck Theory
- Long term effects of eruption include: drought, loss of vegetation, long term deforestation
- Massive decrease in human population: only 3,000 to 10,000 survivors
- Decrease in diversity: less genetic variation in present day humans
Or not?
- East Africa did not have a Volcanic Winter based on the mud layer where Toba ash was found in Lake Malawi
- Tools found in India were similar before and after the eruption - although this may not have been from humans
Short Term Effects
- Caldera
- 15cm ash layer over South Asia
- Killed all life in immediate area
- Volcanic Winter for 6-10 years
- Expelled about 2,800km cubed of magma
The Toba Eruption
Aya, Lakshmi, Nethmi
Bibliography
- "THE TOBA SUPERVOLCANO and HUMAN EVOLUTION." THE TOBA SUPERVOLCANO and HUMAN EVOLUTION. N.p., n.d. Web. 26 Nov. 2014. <http://toba.arch.ox.ac.uk/project.htm>.
- "Toba Catastrophe Theory." Wikipedia. Wikimedia Foundation, 12 Jan. 2014. Web. 28 Nov. 2014. <http://en.wikipedia.org/wiki/Toba_catastrophe_theory>.
- "Chapter 20 - Population Differences in MtDNA." Erectuswalksamongst. N.p., n.d. Web. 29 Nov. 2014. <http://erectuswalksamongst.us/Chap20.html>.
- "Volcano Catastrophe Idea 'dismissed'" BBC News. N.p., n.d. Web. 29 Nov. 2014. <http://www.bbc.com/news/science-environment-22355515>.
- Q, Charles. "Supervolcano Not to Blame for Humanity's Near-Extinction." LiveScience. TechMedia Network, 29 Apr. 2013. Web. 30 Nov. 2014. <http://www.livescience.com/29130-toba-supervolcano-effects.html>.
- Q, Charles. "Did Ancient Volcano Alter Human History?" LiveScience. TechMedia Network, 10 July 2007. Web. 30 Nov. 2014. <http://www.livescience.com/1661-ancient-volcano-alter-human-history.html>.
- BBC News. BBC, n.d. Web. 28 Nov. 2014. <http://www.bbc.co.uk/schools/gcsebitesize/geography/natural_hazards/volcanoes_rev4.shtml>.
- Wikipedia. Wikimedia Foundation, n.d. Web. 28 Nov. 2014. <http://en.wikipedia.org/wiki/Supervolcano#Known_supereruptions>.
- "Volcanic Explosivity Index." Wikipedia. Wikimedia Foundation, 29 Nov. 2014. Web. 30 Nov. 2014. <http://en.wikipedia.org/wiki/Volcanic_explosivity_index>.
- "Volcanoes Around The World." Geological Society -. N.p., n.d. Web. 29 Nov. 2014. <http://www.geolsoc.org.uk/ks3/gsl/education/resources/rockcycle/page3531.html>.
- "Supervolcanoes." Supervolcanoes. N.p., n.d. Web. 29 Nov. 2014. <http://www.coolgeography.co.uk/GCSE/AQA/Restless%20Earth/Supervolcanoes/Supervolcanoes.htm>.
- "Toba Caldera : Image of the Day." Toba Caldera : Image of the Day. N.p., n.d. Web. 28 Nov. 2014. <http://earthobservatory.nasa.gov/IOTD/view.php?id=7380>.
- "Caldera Toba | Indonesian Volcano | Lake Toba | Toba Caldera Complex."Caldera Toba | Indonesian Volcano | Lake Toba | Toba Caldera Complex. N.p., n.d. Web. 28 Nov. 2014. <http://www.virtualuppermantle.info/Toba-Caldera.htm>.