How is it possible? How can a blow-up of super-volcanoes spread to cover entire continents with ash!? Wind and the initial force of the eruption are not enough to carry the ash over such long distances! An examination of prehistoric eruptions has unveiled the mysteries of all these queries.
It is not possible to make a direct study of such a phenomenon. Super-volcanoes are classified as volcanoes that spew out more than a trillion tonnes of material when they erupt. This amount is equivalent to 30 Krakatoas.
So Peter Baines from the University of Melbourne, Australia, and Stephen Sparks from the University of Bristol, UK, used geological records of ash volume and magma chamber size to estimate the energy of past blasts and model the plumes they would have generated. From this they deduced that the Earth’s rotation fans ash out into a giant spinning cloud up to 6000 kilometres wide within one day. “It is a bit like a hurricane, but on a much larger scale,” Sparks says.
Via: New Scientist