Krafla

Krafla (Icelandic pronunciation: [ˈkʰrapla]) is a volcanic caldera of about 10 km in diameter with a 90 km long fissure zone. It is located in the north of Iceland in the Mývatn region and is situated on the Iceland hotspot atop the Mid-Atlantic Ridge, which forms the divergent boundary between the North American Plate and the Eurasian Plate. Its highest peak reaches up to 818 m and it is 2 km in depth. There have been 29 reported eruptions in recorded history.

Krafla
Aerial view of Krafla (mountain) and Krafla caldera with Leirhnjúkur in 2008
Highest point
Elevation800 m (2,600 ft)
Coordinates65°44′0″N 16°47′0″W
Geography
Krafla is located in Iceland
Krafla
Krafla
Location in Iceland
LocationIceland
Geology
Mountain typeCaldera
Last eruptionSeptember 1984

Overview
Iceland Mid-Atlantic Ridge map

Iceland is a place where it is possible to see plate tectonics at work. It sits astride the Mid-Atlantic Ridge; the western part of the island nation is part of the roughly westward-moving North American plate, while the eastern part of the island is part of the roughly eastward-moving Eurasian Plate. The north–south axis of the Mid-Atlantic Ridge splits Iceland in two, roughly north to south. Along this ridge many of Iceland's most active volcanoes are located; Krafla is one of these.[1]

Krafla includes the crater Víti, one of two well-known craters by this name in Iceland (the other is in Askja). The Icelandic word "víti" means "hell". In former times, people often believed hell to be under volcanoes. Víti has a green lake inside of it.

South of the Krafla area, but not actually within the caldera is Námafjall, a mountain, beneath which is Hverir, a geothermal area with boiling mudpools and steaming fumaroles.

History

The Mývatn fires occurred between 1724 and 1729, when many of the fissure vents opened up. The lava fountains could be seen in the south of the island, and a lava flow destroyed three farms near the village of Reykjahlíð, although nobody was harmed.

Between 1975 and 1984 there was an volcanic episode within the Krafla volcano, known as the Krafla fires.[2] It involved nine volcanic eruptions and fifteen uplift and subsidence events. This interrupted some of the Krafla drillfields. During these events a large magma chamber was identified at depth by analysing the seismic activity. Some of the spectacular fire-fountaining during these eruptions was caught on film by Maurice and Katia Krafft, and features in the 2022 film, Fire of Love.[3]

Since 1977 the Krafla area has been the source of the geothermal energy used by a 60 MWe power station. A survey undertaken in 2006 indicated very high temperatures at depths of between 3 and 5 kilometres, and these favourable conditions led to the development of the first well from the Iceland Deep Drilling Project, IDDP-1, that found molten rhyolite magma 2.1 km deep beneath the surface in 2009.[4][5]

Krafla magma testbed

Following on from the encounter with molten rock during the drilling of IDDP-1, the Krafla Magma Testbed (KMT[6]) concept has been developed, which envisages the creation of an 'international magma observatory' and further scientific drilling at Krafla in order to deliberately drill into the magma body.[7][8]


Photogallery
  • Krafla volcanic area
    Krafla volcanic area
  • Lava flow during a rift eruption at Krafla, 1984
    Lava flow during a rift eruption at Krafla, 1984
  • Lava ropes at Krafla, June 2007
    Lava ropes at Krafla, June 2007
  • Steams at Krafla, June 2007
    Steams at Krafla, June 2007
  • Sulfur deposits at Krafla, June 2007
    Sulfur deposits at Krafla, June 2007
  • A general view of Krafla, June 2007
    A general view of Krafla, June 2007
  • Mudpots at Hverir, Námafjall, August 2008
    Mudpots at Hverir, Námafjall, August 2008
  • Lava at Krafla
    Lava at Krafla
  • Krafla area
    Krafla area
  • Boiling mudpools
    Boiling mudpools
  • Víti crater and lake
    Víti crater and lake
  • Small lake in Krafla
    Small lake in Krafla

See also

References
  1. Kious, W. Jacquelyne; Tilling, Robert I. (February 1996). "This Dynamic Earth: The Story of Plate Tectonics. Chapter 3: Understanding plate motions - Divergent boundaries". United States Geological Survey. USGS. Retrieved 15 January 2020. The volcanic country of Iceland, which straddles the Mid-Atlantic Ridge, offers scientists a natural laboratory for studying on land the processes also occurring along the submerged parts of a spreading ridge. Iceland is splitting along the spreading center between the North American and Eurasian Plates, as North America moves westward relative to Eurasia.
  2. "The Krafla fires: One of the largest volcanic eruptions of Iceland's modern history". Icelandmag.
  3. "She fell in love with the majesty of volcanoes—and changed how science sees them". Science. January 9, 2023.
  4. http://www.iddp.is/ Iceland Deep Drilling Project
  5. "Surprise magma pocket found in Iceland hints at more 'ticking time bombs'". Science. May 19, 2021.
  6. "Krafla Magma Testbed – Oficial Website – Krafla Magma Testbed".
  7. Eichelberger, J. (June 25, 2019). "Planning an International Magma Observatory". Eos.
  8. https://www.geothermal-energy.org/pdf/WGC/papers/WGC/2020/37027.pdf
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