Iceland geysers: where are they and what are they?

The Geysir geothermal area is one of the most fascinating stops on the Golden Circle. On our Iceland Tour, we never miss it. Here, though, we’ll tell you a bit more about this incredible area of Iceland.
 

What is a geyser?

Geysers are powerful jets of hot water mixed with steam that periodically burst out of hot springs. As secondary manifestations of magma activity, they are closely related to volcanoes. Their rarity depends on the specific conditions required for their formation. In fact, for a geyser to form, a few essential circumstances must come together:

• for a geyser eruption to occur, magma must be close to the Earth’s surface so it can heat the rocks enough to bring the water to a boil;
• there must be a source of water flowing underground; in this case, the water comes from the melting of the Langjökull glacier and flows through the area’s porous lava rock;
• there must be an underground reservoir where the water can collect, along with a silica-lined conduit so that the water rising from the reservoir toward the Earth’s surface cannot seep out.
   

How does a geyser erupt?

The water that collects in the geyser’s conduit is heated by volcanic steam and gases until it reaches boiling point. The temperature at which this happens depends on the pressure exerted by the column of water trapped inside the geyser conduit. When the water boils, a violent burst and expulsion occur. Part of the water, due to decompression, turns into steam. The conduit then fills up again and the process starts over. The largest geysers are found in Iceland, the United States, and New Zealand. In New Zealand there is the Waimangu geyser (in Māori, “black water”), which in 1904 shot a jet 450 metres high.
 

The Geysir geothermal area

Now let’s get to the point! In the Geysir geothermal area, you’ll find the two geysers that made the region famous. The first is the one that gave its name to all the others: the Great Geysir. Geysir erupts only rarely, while the second one, nearby Strokkur, erupts about every 10 minutes, with water jets reaching between 20 and 40 metres in height. Yes, here’s a big reveal: the water jet you see in almost all the photos is not Geysir, but Strokkur.

The reasons why the original Geysir is now almost completely inactive are linked to tectonic activity in the area and invasive human intervention: in fact, hundreds of coins were thrown into the crater as “good luck charms,” ultimately contributing to the clogging of the geyser. 
According to some studies, Geysir tends to erupt in cycles, usually triggered by a powerful earthquake, which then slowly die out. 
But even when it is active, the duration and intervals between eruptions are unpredictable. Frustrated that the country’s most famous attraction was so unreliable, in 1935 the Icelanders dug a channel through the silica deposits around Geysir’s vent in order to lower the water level and encourage new eruptions. It worked for a short time, but then the channel became blocked and the activity stopped again. When it does erupt, it reaches greater heights than Strokkur.
 

If you want to see a geyser erupt, you should set off to discover Iceland. And to do so, there’s no better way than travelling with Sto Gran Tour. Take a look at our 8-day Iceland Tour.