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Department of Geography


Climatic, palaeoenvironmental and human impacts of super-volcanic eruptions

The Youngest Toba Tuff (YTT) eruption of Toba volcano in Northern Sumatra, Indonesia, around 74,000 years ago was one of the largest in the entire geological record and impacted climate on the global scale. The effect was a cooling of surface temperatures due to the generation of a globally-dispersed stratospheric sulphate aerosol veil. Catastrophists link the eruption to the onset of a glacial period and a corresponding ‘bottleneck’ in human genetic diversity, akin to a near-mass extinction of our early ancestors. Others believe the global climatic effects from the eruption were less severe. Given that the eruption potentially had a massive impact on early human dispersal patterns and evolution, in addition to extreme forcing of global climate, remarkably little is known about the eruption source parameters and the effect on local environments.

Image as described adjacent

Fossil tree in YTT ash deposit, Jurreru River valley, Andhra Pradesh, India

Image as described adjacent

Map showing field locations investigated during a 2009 field campaign

This project involves PhD student Emma Gatti, who is supervised by Dr. Clive Oppenheimer and Dr. Phil Gibbard. Dr. Hans Graf has also been investigating the possible impacts of the Younger Toba Tuff eruption via climate modelling.


  • Gatti, E., Durant, A.J., Gibbard, P.L. & Oppenheimer, C., Youngest Toba Tuff in the Son Valley, India: a weak and discontinuous stratigraphic marker, Quaternary Science Reviews, in press.

  • Oppenheimer, C., 2011, Eruptions that shook the world, Cambridge University Press, 408 pp.

  • Petraglia, M.P., Korisettar, R., Boivin, N., Clarkson, C., Ditchfield, P., Jones, S., Koshy, J., Lahr, M., Oppenheimer, C., Pyle, D., Roberts, R., Schwenninger, J.L., Arnold, L., and White, K., 2007, Middle paleolithic assemblages from the Indian subcontinent before and after the Toba super-eruption, Science, 317, 114-116.
  • Witham, C.S. and Oppenheimer, C., 2005, Mortality in England during the 1783-4 Laki Craters eruption, Bulletin of Volcanology, 67, 15-26.
  • Mason, B.G., Pyle, D.M. and Oppenheimer, C., 2004, The size and frequency of the largest explosive eruptions on Earth, Bulletin of Volcanology, 66, 735-748.
  • Oppenheimer, C., 2003, Climatic, environmental and human consequences of the largest known historic eruption: Tambora volcano (Indonesia) 1815, Progress in Physical Geography, 27, 230-259.
  • Oppenheimer, C., 2003, Ice core and palaeoclimatic evidence for the great volcanic eruption of 1257, International Journal of Climatology, 23, 417-426.
  • Oppenheimer, C., 2002, Limited global change due to largest known Quaternary eruption, Toba ≈74 kyr BP?, Quaternary Science Reviews, 21, 1593-1609.