These images show the geysir erupting from the start as the waters begin to bubble through to the giant spurt in the air as it reaches it's peak.
I thought it was better to show this from start to finish rather than individual images so added them all to a black background.
Strokkur stopped erupting in 1937 but in 1963 it was cleaned out and it was discovered that it's pipes were blocked due to stones that had been thrown in to encourage it to spout.
The eruption is caused by steam forming in the 40ft deep pipe and this then forces the water upwards, starting as a ball of water that bursts skywards as the steam escapes.
Beware - face the wrong direction and you WILL get wet!!