Global Volcanism Program | Image GVP-07619
Ilopango caldera is seen here from the NE with the southern caldera wall in the background. The 8 x 11 km wide caldera was formed during four major Quaternary eruptions, the last of which occurred about 1500 years ago. The southern caldera wall rises about 500 m above the lake, which has a maximum depth of about 250 m. The small island at the left side of the lake (above the flowering shrub) is Isla Cerro los Patos, a post-caldera dacitic lava dome.
Photo by Lee Siebert, 1999 (Smithsonian Institution).