Global Volcanism Program | Image GVP-03677
The flat area in the foreground of this view of Nevado de Colima is the moat of a large horseshoe-shaped caldera that preceded the construction of the modern Colima volcano. The steep headwall of the caldera forms the forested, arcuate ridge in the center, left of the moat. The caldera was formed by collapse of an ancestral Colima volcano that was constructed south of Nevado de Colima. The slopes of modern Colima volcano, which has filled much of the caldera and overtopped in on three sides, appear at the lower right.
Photo by Jim Luhr, 1981 (Smithsonian Institution).