Imbabura is a volcano in the southern Ring of Fire. As the Nazca Plate is subducted beneath the South American Plate, the former melts with exposure to the hotter asthenosphere. This melted rock, which is less dense than the crust above it, rises to the surface. The result is an arc of volcanoes, which includes Imbabura, 100-300 km away from the subduction zone.