5 Volcanoes You Should Keep Your Eye On

OurAmazingPlanet:  Italy's Mount Etna and Mexico's Popocatépetl volcano have been huffing and puffing their way into the news recently, spewing plumes of ash and dribbling lava in the latest flare-ups of eruptive activity that have been going on for years in the case of both volcanoes.

While larger eruptions, such as the Philippines's Pinatubo in 1991 and the 1980 blast of Mount St. Helens in Washington, are more famous for the disruptions they caused, some near-constant eruptions have their own associated hazard, posing threats to nearby communities and potential disruptions to air traffic from ash plumes.

Here are five volcanoes that don't always get a lot of fanfare, but have been quietly (or maybe not so quietly) rumbling and spitting up volcanic material continuously for years — even decades — in order of the number of years they've been erupting.