Volcanoes in Iceland

from Wikipedia, the free encyclopedia
Volcanoes in Iceland (Iceland)
Invisible Square.svg
Invisible Square.svg
RedMountain.svg
Invisible Square.svg
Öræfajökull
Öræfajökull
Esjufjöll
Esjufjöll
Hengill
Hengill
Snæfellsjökull
Snæfellsjökull
Ljósufjöll
Ljósufjöll
Bárðarbunga \ \ \ \
Bárðarbunga    
\   
\  
\ 
\
Kverkfjöll
Kverkfjöll
Kerlingarfjöll
Kerlingarfjöll
Hofsjokull
Hofsjokull
Langjokull
Langjokull
Þeistareykir
Þeistareykir
Krýsuvík
Krýsuvík
Eyjafjallajokull
Eyjafjallajokull
Torfajokull
Torfajokull
Reykjanes
Reykjanes
Active volcanic zone and systems in Iceland, as well as the main volcanoes

In the North Atlantic , the numerous volcanoes of Iceland have created and shaped the main island of the same name as well as a number of smaller islands such as the Westman Islands or the small islands and skerries in the Breiðafjörður fjord . Iceland is one of the few parts of the Mid-Atlantic Ridge that towers above the sea surface.

Geological conditions

There are around 31 active volcanoes in Iceland , with geologists considered to be any volcano that has erupted in the last 10,000 years. However, every volcano has its own rhythm and within it its own phases of more intense and less intense eruption activity, and so there are also volcanoes such as the Grímsvötn or the Hekla , which erupt approximately every four or ten years.

The special density of volcanoes on Iceland is explained by the location on the mid-Atlantic ridge , a rift zone , and by a suspected plume in the mantle below the island, the Iceland plume . The Mid-Atlantic Ridge is mostly an underwater mountain range and consists of two almost parallel mountain ranges with a deep rift in between. It only rises above the sea surface in a few places. One of these places is Iceland. The line of the volcanically active zone follows the course of the Mid-Atlantic Ridge. Magma comes to the surface of the earth through the cracks between the drifting plates, the North American and the Eurasian .

This zone, where most of the island's active volcanoes are located, runs roughly diagonally across Iceland from southwest to northeast: from Reykjanes to Langjökull in the west, from the Westman Islands via Mýrdalsjökull and Vatnajökull to Þeistareykir in the east. In the middle of the country you can see a deviation to the east. The zone of most fissures and tensions lies between these two active mountain ranges and therefore the strongest earthquakes take place there, cf. the one with the epicenter at Selfoss in 2000. A microplate , the Hreppar plate, is suspected here .

Many of the volcanoes that were already active in the Pleistocene were also active in the Holocene . On average, one of the active volcanoes erupts every five years. After the shield of the last ice age melted, very large effusive eruptions seem to have taken place, producing up to 15  km³ of lava. The shield volcanoes such as Skjaldbreiður , Trölladyngja and Ketildyngja are witnesses of this. Later, more explosive eruptions occurred again, such as a major Hekla eruption 2800 years ago , which ejected 3 km³ of tephra . But there were also powerful explosive eruptions before that, for example when Jökulsárgljúfur was formed about 300,000 years ago.

The belt of active volcanoes, and thus the plate boundary, was not always in the same place. A few million years ago the belt did not lie over the Reykjanes Peninsula , but further out in Faxaflói Bay , led from there over the Snæfellsnes peninsula and in an arc to the north to what is now the Húnavatnssýsla district and then north of the country. When the fire of this volcanic belt dried up, the location of volcanic activity shifted to where it is today.

The Snæfellsnes peninsula is an exception to the rule. There, after a pause of several million years, about four million years ago, another phase of activity began, so that one has to speak of a volcanically active zone outside the rift zone . After all, there are three active volcanic systems on Snæfellsnes, of which Snæfellsjökull is the best known.

The main volcanoes

14 of Iceland's numerous volcanoes have been active over the past 100 years.
The map and timeline show the location and eruptions of Iceland's most famous volcanoes. (Graphic: eskp.de/CC BY)

The main volcanoes in Iceland are:

In the south and west of the country: Hekla , Mýrdalsjökull with Katla , Eldgjá and the Laki craters , Hvannadalshnjúkur (or Öræfajökull ), Esja , Snæfellsjökull , Ljósufjöll and Baula .

In the north of the country and in the Icelandic highlands : the glacier Vatnajökull with Bárðarbunga , Grímsvötn and the Kverkfjöll (see also: Glacier Run ) as well as the volcanoes Krafla , Hverfjall , Askja and Herðubreið as well as the Kerlingarfjöll near Hofsjökull . In the southeast there is also Snæfell , the highest mountain and volcano in Iceland outside of Vatnajökull.

There are also some very active volcanoes on the Vestmannaeyjar (Westman Islands) such as B. on Surtsey or the Eldfell on Heimaey . Their system is probably linked to Mýrdalsjökull , as one had to find disappointed during research work on a possible tunnel project between the Westman Islands and the mainland: the seabed there is far too hot for a tunnel.

The area of ​​the Hengill central volcano with Hveragerði and the Haukadalur in southern Iceland with the well-known geysers also belong to the volcanically very active high-temperature areas .

Active volcanic systems and their central volcanoes

"Active" is understood here to mean volcanoes that had their last eruption within the last 10,000 years, and can therefore be considered dormant in some cases (such as Snæfellsjökull ):

highest point -
central volcano		 Height
(m)		 Mountain range -
volcanic system
Hvannadalshnúkur -2110 Öræfajökull
Bárðarbunga -2010 Bárðarbunga, Vatnajökull
Austur-Kverkfjöll -1933 Kverkfjöll
Snæfell -1833 Snæfell
Hofsjokull -1765 Hofsjokull
Grímsvötn -1720 Grímsvötn, Vatnajökull
Eyjafjallajokull -1666 Eyjafjallajokull
Tungnafellsjokull -1535 Tungnafellsjokull
Esja, Esjufjöll -1522 Esjufjöll, Vatnajökull
Askja -1510 Dyngjufjöll
Hekla -1491 Hekla
Snækollur -1482 Kerlingarfjöll
Ýme -1462 Tindfjallajokull
Skaftárkatlar -1460 Grímsvötn
Katla -1450 Myrdalsjokull
Snæfellsjökull -1446 Snæfellsjökull
Hveravellir -1355 Langjokull
Prestahnúkur -1220 Prestahnúkur, Langjökull
Torfajokull -1190 Torfajokull
Ljósufjöll -1063 Ljósufjöll
Kaldnasi, Helgrindur massif 0−988 Lýsuskarð
Ketildyngja 0−939 Fremri-Namur
Krafla 0−818 Krafla
Skeggi 0−803 Hengill
Hrafnabjörg 0−763 Hrafnabjörg
Laugarfjall 0−700 geyser
Vífilsfell 0−655 Brennisteinsfjöll
Þeistareykjabunga 0−564 Þeistareykir
Hrómundartindur 0−561 Hrómundartindur
Álútur 0−471 Grensdalur
Trölladyngja (Reykjanesskagi) 0−275 Krýsuvík
Þorbjörn 0−243 Svartsengi
Seyðishóll 0−214 Grímsnes volcanic system
Eldfell, Heimaey 0−200 Westman Islands
Surtsey 0−154
Gunnuhver −0040 Reykjanes volcanic system
Kolbeinsey −0005 Kolbeinseyrücken submarine
volcanic system
Njörður 0−400 Reykjanes Ridge

See also

Individual evidence

  1. ↑ cf. z. BHU Schmincke or the American geologist Elisabeth Cotrell from the Smithsonian Institute: "... we call any volcano“ active ”if it has erupted in the last 10,000 years" [1] Accessed May 7, 2010
  2. ↑ http://www.norvol.hi.is/pdf/wvz.pdf Freysteinn Sigurdsson: Iceland's Western Rift Zone - Field Trip

literature

  • Ari Trausti Guðmundsson : Living Earth. Facets of the geology of Iceland . Mál og Menning, Reykjavík 2007, ISBN 978-9979-3-2778-3 .
  • Ari Trausti Guðmundsson, Halldór Kjartansson: Land in becoming. An outline of the geology of Iceland . Vaka-Helgafell, Reykjavík 1996, ISBN 9979-2-0347-1 .
  • Christof Hug-Fleck: Iceland's natural wonders. 4th completely revised edition, C! H! F Verlag, Au 2010, ISBN 978-3-00-030427-9 .
  • Thor Thordarson, Armann Hoskuldsson: Classic Geology in Europe, 3 - Iceland . Terra, Harpenden 2002, ISBN 1-903544-06-8 .

Web links

Photos and videos

Commons : Volcanoes in Iceland  - Collection of images, videos and audio files

General and volcano monitoring

Scientific contributions

Other