Photos: Ancient Supereruptions in Idaho's Snake River Plain

Volcanic Deposits

Southern Idaho Canyon — (Image credit: David Finn, University of California, Santa Cruz)

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.

Ancient Eruptions

Study author Tom Knott at a thick ash-deposit formed by a fast-moving "pyroclastic flow."

Reading Between the Folds

Snake River Ignimbrite — (Image credit: Marc Reichow, University of Leicester)

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.

Canyon View

Each layer in this canyon represents an individual giant eruption.

Yellowstone Supervolcano

In Yellowstone National Park, the rim of a supervolcano caldera is visible in the distance.

Evidence of a Supereruption

Lava from Yellowstone supervolcano made form hardened ash — (Image credit: Graham Andrews, assistant professor at California State University Bakersfield.)

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.