Strokkur

Strokkur (Icelandic, "churn") is a fountain-type geyser located in a geothermal area beside the Hvítá River in Iceland in the southwest part of the country, east of Reykjavík. It typically erupts every 6–10 minutes. Its usual height is 15 - 20 m, although it can sometimes erupt up to 40 m high.

Location
Strokkur belongs to the Haukadalur valley area, where various other geothermal feature such as mud pools, fumaroles and other geysers are located around it, such as the famous Geysir geyser, which lies only 50 m to the north.

History
Strokkur was first mentioned in 1789, after an earthquake helped to unblock the conduit of the geyser. Its activity fluctuated throughout the 19th century; in 1815 its height was estimated to have been as much as 60 m. It continued to erupt until the turn of the 20th century, when another earthquake blocked the conduit again. In 1963, upon the advice of the Geysir Committee, locals cleaned out the blocked conduit through the bottom of the basin, and the geyser has been regularly erupting ever since.

Tourism
Strokkur and its surrounding areas regularly attract tourists hoping to see the geyser erupt, as it is one of a very few natural geysers to erupt frequently and reliably.

Evolution of the eruption
Each frame is approximately 1/4 of a second apart, for a total of approximately two seconds: