The U.S. Geological Survey said that it is classifying 18 volcanoes in the United States as having a “very high threat,” and it classified the Yellowstone volcano in Wyoming as “high.”
The USGS updated its volcano threat assessments list for the first time since 2006.
It said that “11 of the 18 volcanoes are located in Washington, Oregon, or California, where explosive and often snow- and ice-covered edifices can project hazards long distances to densely populated and highly developed areas.”
The danger list is topped by Kilauea in Hawaii, which has been erupting continuously in 2018.
Mount St. Helens as well as Mount Rainier in Washington, Alaska’s Redoubt Volcano, and California’s Mount Shasta are also the top five, the USGS said.
Alaska’s Mount Okmok, Akutan Island, and Mount Spurr also saw higher threat scores than in 2006, the USGS said.
The USGS has threat assessment levels of very low, low, moderate, high, and very high.
“Five of the 18 very high threat volcanoes are in Alaska near important population centers, economic infrastructure, or below busy air traffic corridors. The remaining two very high threat volcanoes are on the Island of Hawaii, where densely populated and highly developed areas now exist on the flanks of highly active volcanoes,” the agency said.
It added: “The high- and moderate-threat categories are dominated by Alaskan volcanoes. In these categories, the generally more active and more explosive volcanoes in Alaska can have a substantial effect on national and international aviation, and large eruptions from any of the moderate- to very-high-threat volcanoes could cause regional or national-scale disasters”
Threat scores rose for Oregon’s Newberry Volcano as well as Wyoming’s Yellowstone. The Yellowstone caldera is listed as “high” by the USGS.
There are 161 active volcanoes in the U.S.