The explosiveness of a volcanic eruption depends on how many gas bubbles form in the magma—and when. Until now, it was thought that gas bubbles were formed primarily when the ambient pressure dropped ...

Volcanic eruptions are perhaps nature's most terrifying display of power. Catastrophic eruptions of volcanoes like Mount Vesuvius, Krakatoa, and Mount St. Helens have gone down as some of the most ...

Some volcanoes, such as the Cascade volcanoes up in Washington and Oregon, are of the type called a stratovolcano. These steep volcanoes sometimes erupt explosively and other times have calmer lava ...