The discovery points to a different mechanism behind these rare supereruptions, compared with regular volcanoes that frequently erupt. The study, published today (Oct. 30) in the journal Science, could help explain how supervolcanoes store enormous quantities of magma before their terrifying blasts.
"I think this is a distinctive feature of this volcano, and it's related to the style in which it erupts," said study co-author Christoph Sens-Schönfelder, a seismologist at the GFZ German Research Centre for Geosciences. "The geodynamic models that explain structures like those suggested by our results predict that it takes millions of years to accumulate the required magma volumes," Sens-Schönfelder told Live Science.
One of the most puzzling features of supervolcanoes is their skill at storing massive amounts of magma without bursting. When the Toba supervolcano erupted 74,000 years ago, an enormous 700 cubic miles (2,800 cubic kilometers) of lava and ash spread from Africa to Australia. Even though the last Toba blast spread ash from Africa to Australia, the volcano actually had little effect on climate in East Africa, where modern humans were undergoing an apparent near-extinction, according to recent research. In comparison, the 1883 Krakatoa eruption, one of the largest in recent history, spewed about 3 cubic miles (12 cubic km) of material. [Big Blasts: History's 10 Most Destructive Volcanoes]