(CNN) -- Mount Redoubt volcano in southern Alaska erupted four times on Friday, shooting ash as high as 51,000 feet, scientists said. The latest eruption took place at 8:30 p.m. (12:30 a.m ...

Anchorage, Alaska (CNN)-- It's 3 degrees and snowing outside the Alaska Volcano Observatory in Anchorage, but inside the operations center, things are heating up. "This is kind of the nerve center ...

The volcanoes featured in the NOVA program "Volcano's Deadly Warning"—Galeras, Nevado del Ruiz, Popocatepetl, and Mt. Redoubt—as well as many other famous volcanoes, including Mt. St.