Iceland

Strokkur Geyser

Strokkur Geyser is one of the most famous, albeit not a very big, geysir. It is located in Haukardalur, in the same geothermal field as the now inactive "Great Geyser" whose regular activity stopped about a century ago, but resumed erupting mildly and irregularly after some earthquake activity in the year 2000. During the past decades, Strokkur Geyser changed its former unpredictable activity into a fairly regular one, with small eruptions lasting few seconds every few minutes.

Strokkur Geyser
A large steam bubble suddenly rises through the geyser conduit (light blue) and lifts the water in the pond which, for an instant, forms a bubble roughly 2 metres in diameter.
Strokkur Geyser
Then the steam breaks through the top of the bubble, which explodes and creates many jets of water droplets. In the pond a wave travels outwards.
Strokkur Geyser
At the climax of the steam eruption, most of the water column is ejected from within the vent as more waves temporarily enlarge the pond's diameter.
Strokkur Geyser
At the end of the eruption, which has lasted only a few seconds, most of the water flows back into the conduit, where it will heat up and finally erupt again.
Strokkur Geyser
Sometimes a minor eruption occurs right after a bigger one: in this case the explosion occurs without the initial bubble surge.
Strokkur Geyser
Wide angle view of the onset of an eruption: tourists in the background give the (small) scale.
Strokkur Geyser
The column of steam mixed with water droplets rarely reaches higher than about 20 metres, well short of the 60 metres, the "Great Geyser" used to reach.
Strokkur Geyser
The geothermal field of Haukardalur is rich in thermal phenomena: a small pond with a permanent erupting spring, reaching about half a metre in height.
Strokkur Geyser
Another steam bubble uplifts the blue water of Strokkur Gayser.
Strokkur Geyser
The steam explodes in a column of water and vapour.
Strokkur Geyser
Note the first bubbles on the water surface.
Strokkur Geyser
Explosion of steam in Strokkur Geyser.
Photos by Marco Fulle, 11 Sept 2007, midday, and 13 Apr 2010 (third row of photos).