Hello Sarah - I think that a lot of the information you are looking for is in our National Volcano Early Warning System (NVEWS) document, here: https://pubs.usgs.gov/of/2005/1164/2005-1164.pdf Volcanic threat is the combination of hazards from a volcano, and people and property at risk from those hazards (exposure). NVEWS developed a threat ranking based on these two factors - you can read more about it in the document. As only about half of the most threatening volcanoes are seismically instrumented, we are under-monitored for volcanic threats. We have added and improved instrumentation at some volcanoes since the first version of this document was written in 2005, but there is still a sizeable monitoring gap. (A new version of the NVEWS document is being written, but is not yet published.) Regarding the most dangerous volcano in the US, *currently* - my personal *opinion* would split into two groups: --for aircraft: a frequently-active volcano in Alaska. As Bogoslof is the one currently erupting RIGHT NOW that would be an obvious pick, but volcanoes like Pavlof and Akutan also fall into this category. --for people and infrastructure, the Cascade Volcanoes would definitely make the list. Picking one of them, I'd probably choose Rainier - for it's obvious eruption and non-eruption related hazards. (you can read more about Rainier on CVO's website.) Best wishes on your studies, Cheryl Cameron -------- Sarah Lusty wrote: I am currently a student (age 16) in the United Kingdom. After having an amazing trip visiting US volcanoes in the summer, I have developed an interest in finding out more. I am writing an extended assessed essay at school titled: "What is the most dangerous volcano in the USA?" which I have chosen as my area of interest to research. I have 3 questions which I would love your expert opinion on: • What do you think makes a volcano dangerous? (what is the main parameter for danger eg. How close it is to people) • Do you think the US invests enough money in natural hazard monitoring, are there enough systems in place? • What do you think is the most dangerous volcano in the USA, currently? Why? Thank you for your help, it will be invaluable. Sarah Lusty -- Cheryl Cameron Geologist, Alaska Volcano Observatory Alaska Division of Geological & Geophysical Surveys voice: 907-451-5012 fax: 907-451-5050