Geological Society Working Group

It’s not a question of “if” - it’s a question of when…Many large volcanoes on Earth are capable of explosive eruptions much bigger than any experienced by humanity over historic time. Such volcanoes may be termed super-volcanoes and their colossal eruptions super-eruptions. The occurrence of a super-eruption would have severe environmental effects and might threaten global civilisation. Events at the smaller scale end of the super-eruption size spectrum are quite common when compared to the frequency of other naturally occurring devastating phenomena such as asteroid impacts. The effects of a medium scale super-eruption would be similar to those predicted for the impact of a 1 km-diameter asteroid with the Earth, but even super-eruptions of this size are still 5-10 times more likely to occur within the next few thousand years than an impact.

On this site:

http://www.geolsoc.org.uk/template.cfm?name=Super1