I am asking on behalf of a friend who would like to do a special study of the volcanic hazard. Chris Durbin Hi Chris, That is another difficult question, and one that volcanologists are likely to disagree on.
Risk adds the human element to the picture, namely, what damage are the ash, flows, quakes etc.
For example, there is a large volcanic hazard on the Galapagos island volcano of Fernandina. It erupts relatively frequently, its lava flows travel swiftly down the slopes, and it has been known to be explosive. Of course if you care about iguanas and Galapagos Hawks it is another story. So, in your quest to find the most dangerous volcano you need one with a high geological potential to produce dangerous products and events as well as a large nearby human population. On the other hand it is in a relatively developed country with a long history of volcanic studies, which reduces the risk somewhat.