Ash Plume Streams from Mt. Etna, Sicily
When this southward-looking photograph was taken by the Expedition 2 crew aboard the International Space Station, the city of Catania (in shadow, ~25 km SSE of the volcano) was covered by a layer of ash and Fontanarossa International Airport was closed. On that day an ash cloud was reported to have reached a maximum height of ~5.2 km. Plumes from two sources are visible here—a dense, darker mass from one of the three summit craters and a lighter, lower one.
The record of historical volcanism of Mt. Etna is one of the longest in the world, dating back to 1500 BC. Two styles of activity are typical: explosive eruptions, sometimes with minor lava flows, from the summit craters and flank eruptions from fissures.
Addittional sources of information:
Smithsonian Global Volcanism Program