blog posts Supervolcanoes may erupt when cracks form in the roofs of the chambers holding their molten rock Nov 19, 2015 10:30 am by Discovery NewsIllinois in the News Share on Facebook Tweet Email Images Discovery News (Nov. 17) - Illinois Volcanologist Patricia Gregg says the infrequency of supereruptions indicates there's a difference between them and smaller, more frequent eruptions. Share on Facebook Tweet Email