Gases emanate from fumaroles within the sulfur-lined wall of a lava dome at the bottom of the Poás active crater. The turquoise-colored crater lake is among the most acidic natural waters on Earth. The hot lake has been the source of frequent phreatic eruptions that produce plumes of steam, ash, and mud.

Photo by Guillermo Alvarado (Instituto Costarricense de Electricidad).

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

Galleries: Geothermal Features

Keywords: fumarole | geothermal | gas | steam | crater lake | crater | sulfur | mineral deposit

Poás