Classifying volcanic activity. Scientists classify the activity of a volcano according to how often it erupts. Active volcanoes erupt constantly. The eruption is generally quiet but occasionally becomes violent. A famous active volcano is Stromboli, which lies on an island off the coast of Italy.
Intermittent volcanoes erupt at fairly regular periods.
Such volcanoes include Mount Asama in Japan, Mount Etna in Sicily, and Hawaii's Hualalai. Dormant volcanoes have become inactive, but not long enough to know whether they will erupt again. Extinct volcanoes have been inactive since the beginning of recorded history. Aconcagua in Argentina and Mount Kenya in Kenya are extinct volcanoes. They probably will not erupt again.