Geyser is a part of the Golden Circle (a popular day excursion from Reykjavik), along with Þingvellir and Gullfoss. What in the world is a Geyser? It is a spring characterized by intermittent discharge of water ejected turbulently and accompanied by steam. In other words, a vertical column of boiling water coming straight out from the ground. You need particular hydrogeological conditions to form geysers, which exist only a few places on earth, so you can safely say that it is a fairly rare phenomenon.
As discussed in this post, Iceland much? Þingvellir (or a stroll between the tectonic plates), Iceland is indeed volcanic, and magma is thus close to the earth surface at this island. Simply put, water makes its way underground and when it gets deep enough (around 2000 meters / 6600 ft.) it gets heated by the rocks that lay atop of the magma. The already pressurized water (pressure alters the boiling point of water) starts to boil and transform into steam, and thus the pressure increases even more. And that is how you get the geyser effect when hot water and steam sprays out of the geysers surface vent in a hydrothermal explosion.
Here is a bit of trivia for ya. Best remember this – it might come in handy in a pub quiz:
The word “geyser” actually comes from an erupting spring at Haukadalur in Iceland, named “Geysir”, which in turn comes from the Icelandic verb “geysa” (to gush, in English), and the verb itself is derived from Old Norse. Think about that for a second; when you go to visit Old Faithful in Yellowstone, or you have to write a paper for geology class, you are actually speaking Icelandic and Old Norse! I have officially taught you two languages! You are welcome!
The geyser in my photos is not Geysir, as it is not currently erupting regularly. However, one of the neighboring geysers, Strokkur (Icelandic for “churn”) erupts every 8-10 minutes with a usual height of 15-20 meters (sometimes up to 40 meters). Strokkur was first mentioned in 1789 after an earthquake helped unblock the conduit of the geyser, and it continued to erupt regularly until the turn of the 20th century, when another earthquake blocked the conduit again. Upon the advice of the Geyser Committee, locals cleaned out the blocked conduit in 1963, and it has been erupting regularly ever since.
The Icelanders, being superstitious people, can of course explain the phenomena with a legend:
Among the people living in the vicinity of Haukadalur there were many wizards. One day hot water flowed between two farms. These particular two farmers were feuding wizards. One of the wizards drove his wizard stick into the ground and started to bite on it to direct the water towards his enemy. The more he gnawed, the more the water attacked his enemy’s house. The enemy, also being a great wizard, in turn drove his wizard stick in the ground and started gnawing on it as well. Quickly the water receded and started to attack the first wizard’s house. After a good while of water wars, the feuding wizards proved to be of equal strength, and the water flowed back to the middle between the farms.
I will leave it up to you to decide what version you trust more, the scientific one or the folkloric one. Personally, I think both explanations of the phenomena are pretty cool.
More of this fantastic island coming up! Please check back!