Alaska: Home of 5 of nation’s highest threat volcanoes

USGS updates its volcano threat assessment list for the first time since 2005

Robust steam and ash emission from Augustine Volcano, March 7, 2006. Photo by Cyrus Reed, USGS, Alaska Volcano Observatory

In its first volcano threat assessment update since 2005, the U.S. Geological Survey includes five Alaska volcanoes among the 18 very highest threats in the nation, including Akutan Island, Augustine, Makushin, Redoubt and Mt. Spurr.

Eleven more in the Pacific Northwest include Mount Baker, Glacier Peak, Mount Rainier and Mount St. Helens in Washington State; Craer Lake, Mount Hood, Newberry and Three Sisters in Oregon; and Lassen, Long Valley Caldera and Mount Shasta in California. Only two of the top 18 are in Hawaii, Kilauea and Mauna Loa, but Kilauea, which has been erupting this year, that has captured the most attention.

The United States is one of the most volcanically active countries in the world, and the volcanic footprint if large, stretching from Alaska in the north to American Samoa south of the Equator, and from Colorado to the Commonwealth of the Northern Marianna Islands in the western Pacific, the report notes.

Lava flows from Kilauea earlier this year inundated some communities, destroying everything in its path, and sending residents fleeing. In Washington State in 1980, eruption of Mount St. Helens also left a path of destruction. When Redoubt erupted in Alaska in 1989, an encounter with an eruption cloud from that volcanoes nearly brought down a jetliner.

Still the updated report released on Oct. 25 by USGS shows that Alaska also dominates in the area of high and moderate threat volcanoes, with 30 volcanoes in each category.

A complete list of all of Alaska’s volcanoes can be found on page 17 of the report, online at https://www.adn.com/alaska-news/science/2018/10/25/alaskas-redoubt-among-18-us-volcanoes-ranked-as-very-high-threat-in-new-assessment/

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There are 161 young, active volcanoes within the borders of the United States, and since 1980, there have been 120 eruptions and 52 episodes of notable volcanic unrest at 44 of those volcanoes, USGS officials note. Volcanic threat assessments are based on 24 hazard and exposure factors.

This latest update, the first in 13 years, adds or raises the threat level for 12 volcanoes and reduces or removes threat level status from 20 volcanoes. USGS notes that the threat ranking is an indicator not of when the volcano will erupt next, but of the potential severity of impacts that could result from future eruptions.

The intent of the assessment is to guide and prioritize risk mitigation efforts through research, hazard assessment, emergency planning and monitoring with partners at the federal, state and local government levels.

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