The principal vent of Jorullo volcano, seen here from the SSE, formed a cinder cone that grew to 250 m in height during the first month and a half of the eruption. Lava flows were erupted at some unknown later time from four flank vents located along a NE-SW fissure cutting through the main cone.

Photo by Jim Luhr, 1996 (Smithsonian Institution).

Michoacán-Guanajuato