In this video excerpt from NOVA: “Deadliest Volcanoes,” learn why the Yellowstone supervolcano is located in the middle of the North American Plate instead of along a plate boundary, where most volcanoes form. Scientist Bob Smith uses a network of seismometers to record seismic waves from earthquakes and construct a three-dimensional model of the magma located beneath Yellowstone. He uses the model to investigate the geologic process responsible for the active volcanism. Data reveal a mantle plume—a column of magma that is rising from deep within Earth’s interior through the North American Plate to create the active volcanism at Yellowstone.

This video is available in both English and Spanish audio, along with corresponding closed captions.