Kverkfjöll

Kverkfjöll
Highest point
Elevation	1,933 m (6,342 ft)
Coordinates	64°39′00″N 16°43′00″W
Geography
Kverkfjöll Location in Iceland
Location	Iceland
Topo map

Warning text about the caves

Kverkfjöll (Icelandic pronunciation: [ˈkʰvɛr̥kˌfjœtl̥] ) is a potentially active central volcano, fissure swarm, and associated mountain range situated on the northern border of the glacier Vatnajökull in Iceland.

It is located in Vatnajökull National Park and at the glacier edge are ice caves and some geothermal features.

The main volume of the Jökulsá á Fjöllum river flows from the Kverkfjöll area. The Volga River directly drains the Kverkjökull glacier into the Jökulsá á Fjöllum. These river systems have had significant jökulhlaups during the Holocene that are related to the three active volcanic systems of Bárðarbunga, Grímsvötn and Kverkfjöll but assignment has been difficult to individual volcanic systems.

Geography

The maximum elevation of the central volcano is 1,933 m (6,342 ft), and it is mainly situated under Kverkjökull, an outlet glacier of Vatnajökull. The Kverkjökull icecap to the north-west of this highest point has a maximum elevation of 1,860 m (6,100 ft), and covers two caldera structures that have an area of 30 and 38 km² (12 and 15 sq mi). To the west of Kverkjökull is the Dyngjujökull outlet glacier and to its east is the Skarphéðinsjökull adjacent to the Brúarjökull outlet glaciers of Vatnajökull. To the north of the central volcano there is a fissure swarm striking N20-30°E for 130 km (81 mi) and to the south of the central volcano it is possible that a subglacial fissure swarm extends for 10–25 km (6.2–15.5 mi).

The area north of Kverkfjöll has been altered by large floods originating from the northern part of Vatnajökull with the heights being tindars and hyaloclastite ridges orientated towards the nor-north-east. The Holocene active volcanic fissures are mostly confined to the nor-north-east orientated Kverkfjöll fissure swarm (Kverkfjallarani western ridge), rather than the north-east orientated Kverkárnes fissure swarm (Kverkhnjúkar eastern ridge). The 2014 to 2015 erupted Holuhraun lava field is approximately 10 km (6.2 mi) to the north-west of Kverkfjöll but is related to the adjacent Bárðarbunga volcanic system.

Geology

Wile the dominant magma is tholeiite basalt, samples of some rocks carried in the Kverkjökull glacier have been silicic and presumably originate from the central volcano, which is a stratovolcano. There is a geothermal field just beyond the western rim of the northern most caldera. This has created an ice–dammed lake called Gengissig. The oldest identified rocks are 780,000 years old.

The tectonic context is that the Kverkfjöll volcanic system is part of the divergent plate boundary northern volcanic zone of Iceland slightly to the north-east of the central volcanoes of the Grímsvötn and Bárdarbunga that are inferred to be closer to the Iceland mantle plume. The mantle is at about 40 km (25 mi) depth under Kverkfjöll, with lower crustal magma intrusion to pockets that are about 10 km (6.2 mi) deep, and its hydrothermal system being driven by a magma intrusion pocket about 3 km (1.9 mi) deep with the hydrothermal water reservoir being at about 2 km (1.2 mi) deep.

Activity

Tephra studies have identified up to seventy eruptions in the last 6500 years, but the volcano has been in relative repose in the last thousand years and had also been inactive for a period between 3000 to 4000 years ago. An earthquake swarm in 2007 to 2008 near Mount Upptyppingar, which is 40–50 km (25–31 mi) north-east of the Kverkfjöll central volcano was interpreted as a 0.04–0.05 km³ (0.0096–0.0120 cu mi) dyke intrusion.. The most recent volcanic subaerial eruption occurred about 1300 years ago from the northern fissure swarm and produced a lava flow covering about 20 km² (7.7 sq mi). In 2013 a jökulhlaup occurred that emptied the water-filled Gengissig depression hydrothermal area, that is located just north-west to the northern caldera. Further than the flood, due to the release of water pressure, there were subsequent significant hydrothermal explosions in the lake bed. Similar water floods or eruptions may have occurred since the since the mid-17th century. A hydrothermal eruption occurred in 1968 500 m (1,600 ft) to the west of the Gengissig depression, and jökulhlaups from the Gengissig depression occurred in 2002, 1997, 1993, 1987 and 1985. Other low grade, possibly hydrothermal, eruptions assigned to the system, have occurred in 1968, 1959, 1929, 1729 (two), and 1655. At least two very large pre-history Holocene jökulhlaups that have had subsequent lava flows over them could have been generated by Kverkfjöll. Before this a tephra layer called the Fugloyarbanki tephra from 27,000 years ago came from Kverkfjöll.

See also

• Glaciers of Iceland
• Iceland plume
• List of lakes of Iceland
• Volcanism of Iceland
  • List of volcanic eruptions in Iceland
  • List of volcanoes in Iceland

External links

• Kverksfjöll Archived 2021-06-10 at the Wayback Machine in the Catalogue of Icelandic Volcanoes
• Kverkfjöll - picture gallery from islandsmyndir.is
• Photo
• ice cave
• "Kverkfjöll". Global Volcanism Program. Smithsonian Institution. Retrieved 2021-06-25.

References

Sources

• Larsen, Guðrún; Guðmundsson, Magnús T. (2019). "Catalogue of Icelandic Volcanoes:Kverkfjöll". Retrieved 30 March 2024.
• Ranta, E.; Halldórsson, S.A.; Barry, P.H.; Ono, S.; Robin, J.G.; Kleine, B.I.; Ricci, A.; Fiebig, J.; Sveinbjörnsdóttir, Á.E.; Stefánsson, A. (2023). "Deep magma degassing and volatile fluxes through volcanic hydrothermal systems: Insights from the Askja and Kverkfjöll volcanoes, Iceland". Journal of Volcanology and Geothermal Research. 436: 107776. doi:10.1016/j.jvolgeores.2023.107776.
• Óladóttir, B.A.; Larsen, G.; Sigmarsson, O. (2011). "Holocene volcanic activity at Grímsvötn, Bárdarbunga and Kverkfjöll subglacial centres beneath Vatnajökull, Iceland". Bulletin of Volcanology. 73: 1187–1208. Bibcode:2011BVol...73.1187O. doi:10.1007/s00445-011-0461-4.
• Montanaro, C.; Scheu, B.; Gudmundsson, M.T.; Vogfjörd, K.; Reynolds, H.I.; Dürig, T.; Strehlow, K.; Rott, S.; Reuschlé, T.; Dingwell, D.B. (2016). "Multidisciplinary constraints of hydrothermal explosions based on the 2013 Gengissig lake events, Kverkfjöll volcano, Iceland". Earth and Planetary Science Letters. 434: 308–319. doi:10.1016/j.epsl.2015.11.043.
• Hjartardóttir, Á.R.; Einarsson, P. (2012). "The Kverkfjöll fissure swarm and the eastern boundary of the Northern Volcanic Rift Zone, Iceland". Bulletin of Volcanology. 74: 143–162. Bibcode:2012BVol...74..143H. doi:10.1007/s00445-011-0496-6.
• Carrivick, J.L.; Russell, A.J.; Tweed, F.S. (2004). "Geomorphological evidence for jökulhlaups from Kverkfjöll volcano, Iceland". Geomorphology. 63 (1–2): 81–102. doi:10.1016/j.geomorph.2004.03.006.