Namafall hverir & Krafla geothermal field

In the Myvatn area, we also visited Namafall hverir and the Krafla geothermal field.

The area is amazing and interesting from every point. Fumaroles grow from the earth like small smoking hills. The black mud waters, are diverse, some are very liquid, others very dense ... but all of them make you think how all this diversity is possible in a reduced area. The rotthen egg smell is deep! Then for me it was also interesting to see how the lava color changes to indicate when the last eruption occured. The darker it is the closer in time the eruption happened.

Unfortunatelly my knowledge of geology is very poor so, in order to explain what is going on in this field, I have taken portions from the information centers at each place.

Namafall hverir is a "high temperature geothermal area with fumaroles and mud pots. At a depth of 1000m, the temperature is above 200ºC. Along with the steam comes fumarole gas, such as hydrogen sulfide which is responsible for the characteristic hot spring smell in these areas. The hot springs produce considerable sulphur deposits. In previouse centuries sulphur was mined in Iceland to produce gun powder" Extract from the information center at Namafall hverir.

Please read the notes at the information center once you are there. Walking is only allowed in marked areas since the temperature is very hot.


After Namafjall Hverir we headed to the Krafla Geothermal field. In order to better explain what Krafla is I will write an extract from the information center at Krafla:



"Iceland is part of the ocean floor which has been forced up above the sea level by special geological conditions. The "hot spot" located beneath Iceland has played a major role in this process, and one of the places it breaks forth is the Krafla geothermal field, where it is accesible for energy procurement. Nature's forces are still locked in battle and their conflicts take various forms: Steam from seething hot springs, volcanic craters of all shapes and sizes, large and small and rough and smooth streches of lava, the land split into fault blocks.

This area is a central vulcano. Primaveral forces tug the Earth's crust apart and split it with fissures that can be seen on the surface. Roughly 100km long, this fissure zone runs almost due north to Öxarfjördur fjord and south to Mt.Bláfjall. The land to the west and east of the fissures is continiously spreading apart in its respective directions, by an average of 2 cm a year. Stóragjá chasm is a clear example of such tectonic plate drifft. Some fissures have slipped to create a fault landscape Mt. Dalfjall, for example, was formed this way.

Volcanic eruptions are characteristic of such fissures. They create either crater series such as Threngslaborgir, or flow lavas of which Eldá is a fine example."..."



More than 10.000 years ago, this area was covered by an ice-age glacier. The ice hindered the lava from flowing away from the eruption fissure, and it piled up instead into tuff ridges such as Mt.Skogarmannafjöll. Mt.Búrfell, on the other hand, is a table mountain formed when the eruption managed to force its way through the surface of the glacier and fill the whole with lava. In some cases basic lava has formed under the glacier and been transformed into shiny obsidian. Hrafntinnuhryggur (Obsidian ridge) is an example of such phenomenon.


Almost all the hot pools that bubble way near Krafla are solfataras like Hverarönd. Hot strams do not flow from them, except underground - the bathing cave Grjotajá is a famouse instance(...)


One of most typical features of a central vulcano is a bowl shaped caldera which occurs in their centre. More than 100.000 years ago the centre of the vulcano around Leirhnjúkur sank or collapsed by several hundred meters in what must have been a spectacular eruption, to form a caldera some 8-10 km in diameter. Over the long period since then it has gradually filled up with pyroclastic material, lava and ash, which means that it has virtually vanished and can only be seen on carfull examination.



At a depth of 3-8 km beneath Leirhnjúkur is a magma chamber, full of molten lava (magma). At intervals of several centuries the lava forces its way out into the fissures or up to the surface in a fissure eruption, and the land spreads by several meters. Such activity can last for a long time, even as such as a decade, as happened in the eruption series of 1975 - 1984.