If the recent volcanic eruption in Iceland has got you wondering which volcanoes you should be worrying about, and exactly how much to worry about them, you’re in luck.
The United States Geological Surveys Volcano Hazards Program has all the volcano maps and charts you need to make an informed decision about your level of volcano-induced anxiety.
There are 55 dangerous volcanoes in the US. A caveat: this is not a ranking of the volcanoes by their danger level.
As Wendy Stovall, a geologist with USGS, told Business Insider in an email:
There are many volcanoes that are threatening due to factors such as tectonic setting, population density, eruption frequency, and potential to erupt again. The variations in these factors make each of the NVEWS [National Volcano Early Warning System]-designated ‘high threat’ volcanoes uniquely dangerous.
For a full list of volcanoes by threat level, and a thorough description of how they’re monitored, check out pages 20 and 21 of this 2005 volcano report from the USGS. More up-to-date information on individual volcanoes is available on the website for the USGS Volcano Hazards Program.
The volcanoes designated as “Very High Threat” are near large population centres and have the potential to erupt explosively and to trigger lahars — swift, massive landslides of water, mud, and debris that rush downstream after an eruption.
Many of the “High Threat” volcanoes are near smaller population centres and power or transportation infrastructure throughout Alaska. Some of these erupt more frequently, posing significant threats to aviation.
Our lack of comprehensive, up-to-date monitoring raises cause for concern. Ashfall from volcanic eruptions can interfere with electronics, make air travel impossible, and endanger human health. Real-time monitoring can save money as well as lives, by enabling local authorities to predict the impact of a given eruption and respond appropriately.
Here’s the full map of volcanoes in the U.S., from the USGS. This map shows all of the active volcanoes in the US by their alert level. White triangles mark volcanoes with no ground-based monitoring; green triangles mean there’s no imminent cause for concern. The yellow and orange triangles indicate volcanoes that are currently erupting or are likely to erupt soon:
You can see the Aleutian islands (a relatively uninhabited area of Alaska in the Pacific Ocean) is home to a lot of them — 5 “Very High Threat” and 26 “High Threat” volcanoes, as designated in the report. While not located near large populations, eruptions at these volcanoes could significantly disrupt air travel:
In the continental US, most of the volcanoes are concentrated along the West Coast, particularly in the Cascades mountain range, part of the Ring of Fire in the Pacific Ocean. This area is home to most of the active volcanoes in the continental US, including nine “Very High Threat” volcanoes.
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