Fumarole

A fumarole (Latin fumus, smoke) is an opening in the crust of the Earth, often in the neighborhood of dormant volcanoes, where steam and gases come out, for instance carbon dioxide, sulfur dioxide, hydrochloric acid, and hydrogen sulfide.

Sulfureous fumaroles at the Solfatara crater, one of the 24 craters of the Phlegraean Fields, Naples

Fumaroles near the summit on Mount Damavand, Iran

Sulfureous fumaroles on Whakaari/White Island, New Zealand

Fumaroles in Nisyros, Greece

Etymology

The name solfatara (from the Italian solfo, sulfur), is given to fumaroles with sulfurous gases.