The degassing crater lake at the summit of Poás volcano is seen here in 1982. The 800-m-wide crater lies near the center of the smaller of two calderas at the summit. One of the world’s most acidic natural lakes, the diameter and depth varies with seasonal rainfall and eruptive activity; on occasion the lake has disappeared.

Photo by Bill Rose, 1982 (Michigan Technological University).

This image is made available under the Creative Commons BY-NC-ND 4.0 license terms.

Keywords: crater | crater lake | stratigraphy | emissions | gas | stratigraphy | geology | tephra

Poás