solfatara

/ˌsoʊlfəˈtɑrə/
noun
  1. A volcanic vent that emits only gases, especially sulfurous steam, with little or no lava.
    • The hikers could smell rotten eggs near the solfatara in the volcano's crater.
    • Scientists study solfataras to monitor volcanic activity.
    • Yellowstone National Park has many solfataras that release hot sulfur gases.
Synonyms