By SETH BORENSTEIN | The Associated Press
WASHINGTON (AP) — Government scientists are classifying 18 U.S. volcanoes as a “very high threat” because of what’s been happening inside them and how close they are to people. Three are in California.
The U.S. Geological Survey is updating its volcano threat assessments for the first time since 2005. The danger list is topped by Hawaii’s Kilauea, which has been erupting this year. The others in the top five are Mount St. Helens and Mount Rainier in Washington, Alaska’s Redoubt Volcano and California’s Mount Shasta.
The agency says a dozen volcanoes have jumped in threat level since 2005. Twenty others dropped in threat level. There are 161 active U.S. volcanoes.
In addition to Shasta, the California volcanoes categorized as “very high threat” are Lassen and the Long Valley Caldera, in the high desert east of Mammoth Mountain (which is itself a volcano).
Shasta erupted most recently in 1786 and Lassen in 1915. At Long Valley Caldera, recurrent earthquake swarms, changes in thermal springs, gas emissions and uplift have been ongoing for decades.
Of the 18 “very high threat” volcanoes, five are in Alaska, four in Washington, four in Oregon and two in Hawaii.
The USGS report says volcanoes in the Cascade Range in Northern California, Oregon and Washington are particularly dangerous because “explosive and often snow- and ice-covered edifices can project hazards long distances to densely populated and highly developed areas.”
The other California volcanoes on the list are:
High threat: Mono-Inyo Craters, Clear Lake volcanic field, Medicine Lake, Salton Buttes.
Moderate threat: Mono Lake volcanic field, Coso volcanic field, Mammoth Mountain, Ubehebe Crater.
Very low threat: Golden Trout Creek volcanic field.