Super-eruptions can decimate entire regions, and their cocktail of ash and gases can alter the climate. But, even though they eject huge amounts of material, there are very few documented super-eruptions in the geologic record. So we don’t fully understand why they are so big or how often they occur. Now, details of the Yellowstone supervolcanic eruption are documented in a new study published in the journal Geology.

Yellowstone’s ancient eruptions scattered volcanic debris across the northwestern US. There are so many deposits — covering an area…