How Volcanoes Work

Image Described in Caption
 An active fissure eruption at TvashtarCatena, a chain of giant calderas, was recorded by the Galileo Orbiter on November 25, 1999. The eruption has generated a "curtain of fire" that is more than 30 km long and 1.5 km high. Lava flows emanate from the fissure source. Courtesy of NASA.