Fumarole

Synonyms

Mofette; Solfatara; Volcanic fumarole

Definition

A fumarole is a vent in the Earth’s surface from which steam and volcanic gas are emitted.

Distribution and origins: Fumaroles are generally found in the vicinity of volcanoes and are active during and between periods of volcanic activity. Fumaroles occur along cracks and fissures in the Earth’s surface. They also appear in clusters or fields and on the surface of lava flows and thick deposits of pyroclastic flow . Emissions from fumaroles may continue over long periods of time if they are situated above a continuing heat source or they may stop after a short period of time if they occur atop a volcanic deposit that quickly cools.

Fumaroles may appear in different shapes and forms such as a fissure, a phreatic explosion crater, a single or multiple oval opening, and a diffuse, multiple opening. Gases emitted from fumaroles include carbon dioxide (CO₂), sulfur dioxide (SO₂), hydrogen (H₂), hydrochloric acid (HCl), hydrogen...