Mount St. Helens -- What is a volcano? -- Layers of earth -- Kinds of volcanoes -- Eruptions -- Other dangers -- How volcanoes help -- From lava to land -- Dormant volcanoes -- Geothermal energy -- ...

Volcanoes are a powerful force of nature. There are about 1500 active volcanoes on our planet right now. A volcano is an opening in the Earth's crust that allows lava and other volcanic matter to ...

How do volcanoes function beneath their rocky surfaces? What drives the rumbling vibrations, called tremor, that occur when molten rock or gases ...

A volcano that has been dormant for hundreds of thousands of years could be gearing up for a massive explosion, according to ...