By Sid Perkins
A report just released by the U.S. Geological Survey (USGS) ranks the threats posed by the nation’s volcanoes, identifies gaps in monitoring at and around those peaks, and proposes a comprehensive early-warning system for volcanic unrest and eruptions.
The United States and its territories are home to 169 volcanoes that are now erupting, have erupted recently, or became dormant so recently that they may merely be napping. Since 1980, when Mount St. Helens blew its top, a total of 45 eruptions have occurred at 23 of those peaks. Currently, three U.S. volcanoes are erupting: Mount St. Helens, which reawakened in 2004; Hawaii’s Kilauea, which has been continuously active since early in 1983; and Anatahan, a volcanic island about 320 kilometers north of Guam that rumbled to life from dormancy in May 2003.