New evidence for plume beneath Yellowstone National Park

A pair of researchers from the University of Texas has found what they claim is evidence of a plume beneath Yellowstone National Park. In their paper published in the journal Nature Geoscience, Stephen Grand and Peter Nelson further propose that the plume is part of a zone that runs to the park all the way from Mexico. A plume is a still theoretical abnormality that lies at the boundary between the Earth's core and the mantle, and rises through the mantle into the crust—an abnormality that would exist as a vertical stream of magma. As the researchers note, the prospect of a plume beneath Yellowstone has been strongly debated—some have suggested a plume would explain the source of the heat that drives so much surface activity in the park. Others disagree pointing out that it could just as easily be explained by shallow subduction or lithospheric processes. In this new effort, the researchers have taken a new approach to studying the hot spot—they used seismic data obtained from EarthScope's USArray—a project that placed geologic listening stations across North America. The researchers found what they describe as "a long, thin, sloping zone" (approximately 72 by 55 kilometers in size) inside of the mantle where seismic waves were traveling slower than the areas around them—this suggests a section of the mantle that is approximately 600 to 800° C degrees warmer than surrounding areas, and offers strong evidence of a plume..MORE