A 45-mile-wide caldera is brewing under America’s foremost national park. What will happen when it erupts? Greg Breining explores the shocking answer to this question and others in a scientific yet accessible look at the Yellowstone super volcano. When it erupts, much of the nation will be hit hard. Starting with a scenario of what will happen when Yellowstone blows, this fascinating study describes how volcanoes function and includes a timeline of famous volcanic eruptions throughout history.