T
hough Iceland’s (and perhaps the world’s?) most famous geyser is Geysir, when we come to see it we tend to watch the eruptions of the neighboring, much smaller geyser: Strokkur
Geysir is a famous hot spring in the geothermal area of the Haukadalur Valley, located in southwest Iceland. It is one of the attractions on the famous Golden Circle trail, along with Thingvellir National Park and the mighty Gullfoss waterfall.
Geysir’s fame
Geysir is the proper name for a geyser in the Haukadalur Valley. At one time it was the world’s highest-firing geyser, and as it lay close to mainland Europe, a whole category of such places was also named after it.
Geysir itself, when it erupts, can shoot water as high as 70 meters into the air. And although it activates very rarely, it is still the one that gives the whole area its name and makes it famous all over the world.
T
hough Iceland’s (and perhaps the world’s?) most famous geyser is Geysir, when we come to see it we tend to watch the eruptions of the neighboring, much smaller geyser: Strokkur
Right next to Geysir is the Strokkur geyser, which erupts regularly every 5-10 minutes. Today, it is thanks to it that this area – the Haukadalur Valley – is very popular among tourists. Geysers are, after all, a truly unique phenomenon, but the real impression is, after all, precisely when they erupt, and not when they calmly bubble under the surface….
In addition to Geysir and Strokkur, there are also Smiður, Litli-Strokkur and several minor geysers. There are also fumaroles and sulfatars everywhere – hissing “mini volcanoes” or “volcanic valves” that release hot steam and various gases into the air. Very interesting are the yellow sulfur stains along the fumaroles themselves, resulting from crystallization of the sulfur found in the fumaroles’ ‘fumes’. You can read more about such exhalations and other volcanic phenomena in the article Stunning Effects of Iceland’s Volcanism
How a geyser erupts
Around the world, but also in Iceland, which is full of volcanoes, geysers are a very rare phenomenon. This is because several conditions are necessary for their formation and operation.
First of all, we must have a hot – and therefore most likely volcanic – rock located underground, but relatively shallow. Secondly, there must be water flowing onto this rock all the time – there should not be very much water, but it should flow steadily through the porous underground rock. Finally, thirdly, in order to prevent the formation of a hot spring or fumarole, it is necessary to have an underground chamber, terminating at the top with a narrow passage. And all this must be in one place – no wonder active geysers are few in the world.
At Haukadalur, the hot magma rock that lies underground maintains a temperature of about 130 oC. At the same time, water constantly flows into it, filling the geyser chamber. The lower layer of water, lying on top of the hottest rock, heats up quite quickly, finally boiling and evaporating. The bubbles produced in this process rise to the top.
At some point, so many air bubbles form at the bottom of these bubbles that they are unable to break through to the surface. The narrow outlet of the geyser chamber ‘plugs’ it, and the pressure at the bottom continues to rise.
Due to the peculiar structure of the geyser chamber, at a certain point the steam accumulated in the depths can no longer support the column of water above it. A “hollow” space is created on the hottest rocks, into which the column of water from above collapses after a while. Tourists gathered on the surface see at this point that the water table in the geyser momentarily collapses slightly by about 0.5 – 1 m, as if something sucked the water into the Earth’s interior.
At this point, the lower part of the water column falls on the heated rocks and evaporates very quickly, creating a very large amount of water vapor and rapidly increasing its pressure. At the same time, the weight of the water column decreases, by this very evaporated part.
The balance of forces is broken and the steam pressure in the depths easily throws the remaining column of water high into the air, creating a picturesque water-vapor eruption. Tourists on the surface squeal with joy and applaud ….
In place of the fired water flows new water, and the whole process repeats from the beginning ….
Geysir – practical tips
Geysir is a mandatory stop on the route around the so-called Golden Circle, on the northern part of road #35. The trip by car from Reykjavik would take about 1.5 hours, but on the way you should see the Thingvellir park or – coming from the south – the Kerid crater, the town of Fludir and the Reykjadalur river, at which it is definitely worth a stop. On the road #35 there are large parking lots for coaches, hotels, restaurants, a gas station. For individual tourists, a smaller parking lot for cars is located a little higher up, right at the entrance to the geyser area. Today the Geysir itself looks rather inconspicuous (photo below). Therefore, the whole “show is stolen” by the neighboring Strokkur. Read more about it and see a video of its eruption in the article Strokkur – the most visited active geyser in Iceland
Geysir is usually inactive.
