During 2008 three refuge volcanoes, Mt. Cleveland, Okmok Caldera, and Kasatochi erupted within several weeks of each other. Below is a picture of Mt. Redoubt which is part of the ring.
In Cold Justice, there is a scene where the Ring of Fire is mentioned by a pilot. Most pilots in Alaska are well aware of this region.They have to be alert and aware of eruptions. Falling ash can cause great damage to a plane's engine and even make them go down.
Below is a news report about a time when Mt. Redoubt was threatening to erupt. I'm used to seeing volcanoes on tropical islands. It's quite something to see one covered with snow.