Yellowstone magma plume studied

SALT LAKE CITY, Dec. 15 (UPI) -- University of Utah scientists say seismic images of the plumbing feeding the Yellowstone supervolcano show a magma plume much larger than previously thought.

Scientists say they've imaged a plume of hot and molten rock rising at an angle from the northwest at a depth of at least 410 miles, contradicting claims there is no deep plume, only shallow hot rock moving like slowly boiling soup.

A related University of Utah study used gravity measurements to indicate the banana-shaped magma chamber of hot and molten rock a few miles beneath Yellowstone is 20 percent larger than previously believed, so a future cataclysmic eruption could be even larger than projected.

The studies, led by Professor Robert Smith, suggest the same "hotspot" that feeds Yellowstone volcanism also triggered the Columbia River "flood basalts" that buried parts of Oregon, Washington state and Idaho with lava starting 17 million years ago.

"We have a clear image, using seismic waves from earthquakes, showing a mantle plume that extends from beneath Yellowstone,'' Smith said, noting the plume angles downward 150 miles to the west-northwest of Yellowstone and reaches a depth of at least 410 miles,

The study, the Yellowstone Geodynamics Project, was conducted during 1999-2005, using an average of 160 temporary and permanent seismic stations.

The findings from the studies appear in the Journal of Volcanology and Geothermal Research.