A fumarole (Latin fumus, smoke) is an opening in a planet's crust, often in the neighborhood of volcanoes.
They emit steam and gases such as carbon dioxide, sulfur dioxide, hydrogen chloride, and hydrogen sulfide.
The steam is created when superheated water turns to steam as its pressure drops when it emerges from the ground.

Haukadalur Valley on the slopes of Laugarfjall hill, is home to Geysir (The Great Geysir) and Strokkur geyser.
'Geysir' was the first geyser described in a printed source and the first known to modern Europeans.
Research shows that Geysir has been active for approximately 10,000 years.
The oldest accounts of hot springs at Haukadalur date back to 1294, when earthquakes in the area caused significant changes in local neighbouring landscape creating several new hot springs.
Changes in the activity of the Geysir and the surrounding geysers are strongly related to earthquake activity.
In records dated 1630 the geysers erupted so violently that the valley around them trembled.