Seven Volcanoes We Should Be Watching

Popular Mechanics lists seven volcanoes that bear watching:

1.  Popocatépetl, Mexico;

2.  Lokon-Empung, Indonesia;

3.  Mt. Etna, Italy;

4.  Kilauea, Hawaii (U.S.);

5.  Tungurahua, Ecuador;

6.  Nevado del Ruiz, Columbia;

7.  Katla, Iceland.