How Volcanoes Work

 Image Described in Caption
 Ecaudorian Stratovolcanoes -- The city of Otavalo, shown in pink, is surrounded by three dormant stratovolcanoes in the Andes Mountains. Clockwise from upper left, these are Mojanda, Imabura, and Cusin. The summit crater of Mojanda is filled with a lake. The most recent eruption from Mojanda, was about 3,400 years ago. This image was acquired by Spaceborne Imaging Radar aboard the Space Shuttle Endeavor on April 14, 1994. Courtesy of JPL/NASA.