A Blast from Yellowstone's Past

Yellowstone National Park, an active supervolcano, is the site of some of Earth’s largest volcanic eruptions, and as such, presents a significant potential hazard to humankind. It is no surprise that scientists are eager to uncover clues about Yellowstone’s past that could aid in predicting the volcano’s future behavior. The Heise volcanic field in eastern Idaho offers a valuable window into Yellowstone’s past. It was produced by the same mantle plume anomaly that currently fuels volcanism at Yellowstone. But unlike the active Yellowstone center, the Heise volcanic field is now extinct and it preserves a complete record of volcanic activity.

Kathryn Watts is using the entire volcanic record, as preserved in volcanic rock deposits, to determine how magma evolved at the Heise volcanic center. By studying the isotopic signature of individual crystals in its rocks, Kathryn has found striking parallels between Heise and the younger Yellowstone volcanic field. Preliminary results indicate that “cannibalization” (or the re-melting of previously erupted volcanic rocks by basalt from the mantle plume) plays a key role in the evolution of magma at each volcanic center. This cannibalization process characterizes late-stage volcanic activity at both Heise and Yellowstone, indicating that it is a critical component of volcanism and may aid in our understanding of what is in store for Yellowstone’s future.