For additional information on the plate tectonics theory, see the article Plate tectonics . The scientific study of volcanoes is called volcanology. It includes investigating the nature and causes of eruptions and has saved many lives. To aid them in their work, scientists have set up observatories on the slopes or rim of several volcanoes, including Mount Asama in Japan, Kilauea in Hawaii, and Vesuvius in Italy. 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.