The word Geysir came to the English language from Iceland. The original geysir is no longer very active, but the nearby Strokkur ("Little Boy") is still active. There are geysirs in many parts of Iceland, but not all are active.

In the 1980's in Iceland, a TV crew from the U.K. was given permission to prime a semi-dormant geysir in the Hveragerdi area with soap. A TV crew was set up to film, and an announcer was standing in front of the geysir. I was tasked with pouring the soap and scrambling out of harms way, and the cameras started rolling. As the announcer went through her spiel, the geysir became to rumble and hiss. Then it turned into a bubble machine! At first, a few bubbles were coughed out of the geysir like smoke. Then more and more, like the washing machine that 6 year old Bobby filled with dish soap. The film crew couldn't keep from laughing, and the cameras kept rolling. Eventually, the soap gave way to a fountain, which went pretty steady for fifteen minutes, and then gradually subsided.

(Note: it is illegal to pour soap down a geysir in Iceland without permission).

How does a geysir work? Geysirs are found in geothermal areas where there are vertical tubes running throught the ground. Water underground is heated to super-critical temperatures; the temperature rises above the boiling point without any bubbling. The temperature continues to rise, until the water literally becomes explosive. The smallest vibration triggers a sudden release of water vapor, which can be compared to shaking a warm can of soda and lifting the top.