Next month marks the 30th anniversary of the eruption of Mount St. Helens in Washington State. But did you know that in the United States alone there are 169 volcanoes defined as active by the U.S. Geological Survey and that 54 of these are considered to pose a threat to the public? Here’s a map of the 169 from the U.S. Geological Survey [USGS], which is also the source of the map’s caption, as well as the other public domain images and information in this post.
The U.S. Geological Survey (USGS) is responsible for monitoring our Nation’s 170 active volcanoes (red triangles) for signs of unrest and for issuing timely warnings of hazardous activity to government officials and the public. This responsibility is carried out by scientists at the five volcano observatories operated by the USGS Volcano Hazards Program and also by State and university cooperators.
Just this past August (8/20/09), Shishaldin Volcano on Unimak Island, part of Izembek National Wildlife Refuge, Alaska, was erupted. [Photographer: Cyrus Read, U.S. Geological Survey]