Volcanoes repeatedly remind people of Earth's potential for violence. Since 1700, volcanic eruptions have killed more than 250,000 people and devastated scores of communities. What causes these ...

Smoke billows from the mouth of Mt. Shasta like a thunderous cough. Within moments, clear skies turn gray, and the sun vanishes behind thick, shifting layers of volcanic gas and ash. Visitors snap ...

Volcanoes are a natural part of our Pacific Northwest existence – if you lived here during the eruption of Mount St. Helens in 1980, you know that all too well. But even if you weren't here during the ...

Although people are most familiar with Mount St. Helens, a new study shows it is really the Cascade volcanoes in Central Oregon and Northern California that are the most active. Yet, for a volcanic ...

Lassen Peak, shown here, is the southernmost active volcano in the Cascade Mountain Range of western North America, extending from southern British Columbia to northern California. This vast range is ...

Lava is molten rock from a volcano that reaches the Earth’s surface. Liquid rock below the Earth’s surface is referred to as magma. More than 50% of the world’s active volcanoes above sea level ...

Freelance writer Amanda C. Kooser covers gadgets and tech news with a twist for CNET. When not wallowing in weird gear and iPad apps for cats, she can be found tinkering with her 1956 DeSoto. Mauna ...