Viewing an erupting volcano is a memorable experience, one that has inspired fear, superstition, worship, curiosity and fascination throughout the history of mankind. In modern times, volcanic phenomena have attracted intense scientific interest, because they provide the key to understanding processes that have created and shaped more than 80 percent of the Earth’s surface.
Although the role of volcanism in the geology of Earth has long been recognized, its full significance among the geologic processes was not realized until data gathered for the ocean basins revealed extensive basaltic lava flows. The occurrence and effects of volcanism on the planets is also beginning to emerge.