Yellowstone's supervolcano was predated by 12 massive eruptions in Idaho's Snake River Plain, according to new research. These ancient supereruptions took place along the Yellowstone hotspot track, the researchers said. [Read the full story about these ancient supereruptions]
In this photo, a deep canyon in southern Idaho exposes volcanic deposits left behind by several different eruptions.
Study author Tom Knott at a thick ash-deposit formed by a fast-moving "pyroclastic flow."
Reading Between the Folds
When dense volcanic glass welds to the ground, it behaves as an incredibly hot vicious fluid (almost lava-like) that allows a degree of flow within the deposit generating folds.
Each layer in this canyon represents an individual giant eruption.
In Yellowstone National Park, the rim of a supervolcano caldera is visible in the distance.
Evidence of a Supereruption
Evidence of flowing lava hardened into rock found in Idaho several miles away from the site of an 8-million-year-old supervolcano eruption at Yellowstone. The lava was itself formed from superheated ash from the eruption.