Mount Etna, Sicily
One of the most consistently active volcanoes in the world, Sicily's Mount Etna has a historical record of eruptions dating back to 1500 BC. This astronaut photograph captures plumes of steam and possibly ash originating from summit craters on the mountain: the Northeast Crater and Central Crater, which includes two secondary craters (Voragine and Bocca Nuova).
Locals heard explosions coming from the rim of the Northeast Crater on July 26, 2006, and the plumes shown in this image are likely a continuation of that activity. The massive 3,350-meter-high volcano is located approximately 24 kilometers north of Catania, the second-largest city in Sicily, and it dominates the city's northern skyline.
Much of Etna's surface consists of generations of dark, basaltic lava flows that extended outwards from the summit craters. Fertile soils developed on older flows are marked by green vegetation. Although Etna's current explosive eruptions tend to occur at the summit, lava flows generally erupt through fissures lower down on the flanks of the volcano.
Cinder cones, such as Monte Frumento, mark many of the lava flow vents on the volcano's flanks. There is evidence of larger eruptive events as well. The Valle del Bove to the south-southeast of the summit is a caldera formed by the emptying of a subsurface magma chamber during a large eruptive event. Once the magma chamber emptied, the overlying roof material collapsed downwards.
Astronaut photograph ISS013-E-62714 was acquired August 2, 2006, with a Kodak 760C digital camera using an 800 mm lens, and is provided by the ISS Crew Earth Observations experiment and the Image Science & Analysis Group, Johnson Space Center.