Yellowstone Rated High for Eruption Threat
Yellowstone ranks 21st most dangerous of the 169 volcano centers in the United States, according to the Geological Survey's first-ever comprehensive review of the nation's volcanoes.
Kilauea in Hawaii received the highest overall threat score followed by Mount St. Helens and Mount Rainer in Washington, Mount Hood in Oregon and Mount Shasta in California.
Kilauea has been erupting since 1983. Mount St. Helens, which erupted catastrophically in 1980, began venting again in 2004.
Those volcanoes fall within the very high threat group, which includes 18 systems. Yellowstone is classified with 36 others as high threat.
Recurring earthquake swarms, swelling and falling ground, and changes in hydrothermal features are cited in the report as evidence of unrest at Yellowstone.
The report calls for better monitoring of the 55 volcanoes in the very high and high threat categories to track seismic activity, ground bulging, gas emissions and hydrologic changes.
University of Utah geology professor Robert Smith, who monitors earthquakes and volcanic activity in Yellowstone, said more real-time monitoring should be helpful.
"We've really been stressing over the last couple of years that the USGS should consider hazards as a very high priority in their future," he said. "We need to get the public's confidence and the perception that we're doing it right."
The university has joined the Geological Survey and Yellowstone National Park in creating the Yellowstone Volcano Observatory, which uses ground-based instruments throughout the region and satellite data to monitor volcanic and earthquake unrest in the world's first national park.
The USGS report recognizes Yellowstone as an unusual hazard because of the millions of people who visit the park and walk amid features created by North America's largest volcanic system, Smith said, a status he has been advocating for years.