The Reykjanes Peninsula in the southwest of Iceland
|Waters 1||Lake Kleifarvatn|
Bridge between the continents
Reykjanesskagi is a boot-shaped peninsula in the extreme southwest of Iceland , southwest of the capital Reykjavík . The name means Reykjanes Peninsula , whereby Reykjanes ( German "Rauchspitze" or "Rauchhalbinsel" ) nowadays mostly only refers to the extreme southwestern tip, in a sense the heel of the boot.
Plate shift and volcanism on Reykjanesskagi
Reykjanesskagi and the continental drift
The Reykjanes peninsula in southwest Iceland (not to be confused with the same name as in the West Fjords ) is right above the rift zone. The border between two continental plates, the Eurasian and American plates, which diverge from each other at a speed of over 2 cm per year, runs over Iceland. Reykjanes is right on that border. It is said that this is where the Mid-Atlantic Ridge comes ashore, a zone of plate shifts and, at the same time, of active volcanism. Which explains why it appears to be literally the hottest place in Iceland; 300 ° C were measured at a depth of 1,000 m under the central volcano Gunnuhver .
Fracture or rift zones between continental plates are characterized by frequent earthquake activity and the associated earth movements such as the formation of visible fissures and cracks.
A tourist curiosity is the so-called bridge between the continents , which leads over a crack near the Gunnuhver . A display board explains in detail the effect of the plate displacement using the example of Iceland.
Plate displacement effects are also the frequent earthquakes at Lake Kleifarvatn , which u. a. at regular intervals cause the lake to slowly seem to dry out because crevices open beneath it, which then close again so that it fills up again.
The peninsula is made up of formerly subglacial and submarine volcanic formations as well as modern active volcanoes that overlap and overlay each other. With the distance from the Mantle Plume , which is believed to belong to the Grímsvötn , the height of the volcanic mountains from the Hengill down to the Gunnuhver decreases. Directly to the south of Vogastapi are the remains of two submarine volcanic formations made of pillow lavas from the Vistula glacial period .
The oldest rock west of Reykjavík lies in a line from Vogastapi to Garðskagi and consists of lavas of one or more shield volcanoes eroded by glaciers .
Otherwise, in the northwest of Reykjanesskagi, there are three overlapping shield volcanoes, Hrútagjá , Þráinskjöldur and Sandfellshæð (fromW). These three volcanoes are between 9,000 and 10,000 years old and formed in Iceland at the end of the Ice Age. They have a considerable volume of around 15 km³, which is 75% of the total magma volume that has erupted in this part of Reykjanesskagi since the Ice Age.
Other prehistoric lavas include the Búrfellshraun lava field , which was formed around 7,200 years ago and produced by the Búrfell slag crater . It is located about ten kilometers southeast of Hafnarfjörður . A marked hiking trail leads through the so-called Búrfellsgjá , a former lava channel, to the crater. It belongs to the north-western part of the Krýsuvík volcanic system .
Volcanism in historical times (since the 9th century)
The boot-shaped peninsula is also characterized by its huge, relatively young lava fields, which are only very sparsely covered by a thin layer of vegetation. Several series of eruptions took place here in the Middle Ages. The last volcanic eruptions on Reykjanesskagi occurred in the 14th century (Krýsuvík, probably 1340).
Reykjanesskagi is generally characterized by active volcanism , as it is the continuation of the Mid-Atlantic Ridge above sea level . Its segment to the southwest of Iceland is called the Reykjanes Ridge .
Active volcanic systems on the Reykjanes Peninsula
There are three active volcanic systems on the peninsula or, depending on the scientific approach, four active volcanic systems , each named after the adjacent landscapes or mountains (vWnO): Reykjanes with the central volcano Gunnuhver and Svartsengi , Krýsuvík with the central volcano Trölladyngja , sometimes also called the Trölladyngja system , and Brennisteinsfjöll . The series continues to the east with the Hengill , but strictly speaking this no longer belongs to the peninsula. Some geoscientists separate the systems of Reykjanes with the Gunnuhver on the one hand from Svartsengi on the other hand, others see them as a single system.
All of these volcanic systems are arranged more or less parallel to each other and aligned parallel to the rift zone from southwest to northeast.
Reykjanes volcanic system
(see also main article Gunnuhver )
The Gunnuhver spring, the central volcano of the high-temperature region of Reykjanes, changed visibly from 2002 to 2010. Due to the steadily increasing activity, an access road had to be closed with the appearance of new sources (March 08).
The Yngri Stampar crater series belongs to this volcanic system . These produced the last lavas so far on Reykjanesskagi during a major volcanotectonic episode that lasted from 1210 to 1240. During this series of eruptions there were also eruptions in the sea off Reykjanes. B. built the Vatnsfell mountain as a lapilli - tuff structure. Another submarine eruption in 1226 is the origin of a tephra layer , which is used as the so-called medieval tephra all over Reykjanes in tephrochronology .
The Suðurnes power plant benefits from geothermal energy. In 2017, the research company Iceland Deep Drilling Project (IDDP) drilled 4,659 meters deep in 176 days in order to tap and use the volcano's 425 degree hot water, which had a pressure of 340 bar.
(see also main article Svartsengi )
Geothermal energy is also used in the Svartsengi geothermal power station, which is located above the high-temperature area of the same name .
The blue lagoon ( Bláa Lónið ) outdoor swimming pool, which is now extremely modern, uses the hot waste water from the geothermal power plant. The water turned out to be very rich in minerals and has shown healing properties for skin diseases.
(see also main article Krýsuvík )
A volcanic cone that can be seen from afar and characterizes the Reykjanes peninsula from a distance is Keilir , a palagonite cone that was formed during the Ice Age by an eruption at a point under a glacier.
Modern lavas from this system flowed to Hafnarfjörður and are called Kapelluhraun . This is Aa lava , which has its origin in a row of craters approx. 7.5 km east of the road to Keflavík and dates from the 12th century (1151–1188). The Ögmundarhraun lava field near Grindavík originated from the same volcanic tectonic episode .
(see also main article Brennisteinsfjöll )
The volcanic system of the Brennisteinsfjöll stretches far to the northeast, where it meets the volcanic systems of the Hengill and the Hrómundartindur on the Hellisheiði plateau . It includes both the mountains in Reykjavík's Bláfjöll ski area and the boreholes at the high-temperature area of Hverahlíð on Hellisheiði east of Hringvegur .
The Hellnahraun lava field near Hafnarfjörður comes from this volcanic system . Its pahoehoe lavas emerged from the Tvíbollar craters around 920 AD .
UNESCO Global Geopark
In 2015 the region was certified with the UNESCO Global Geopark label due to its geological uniqueness .
From the Middle Ages to the Modern Age
Reykjanes has been settled since the time of the conquest in the 9th and 10th centuries. In the land register , for example, the first settler Grindavík is reported. So this was a certain Molda Gnúpur with his sons.
In the Middle Ages, the cheap landing stages were recognized in many places and the residents of the farms went fishing in winter. Winter fishing villages were also built here in the Middle Ages, to which people from other parts of the country traveled.
Cities and villages
In the 18th and 19th centuries, the population grew in the places with the best landing stages. Villages and cities were formed.
At the beginning of the 21st century, the peninsula is quite densely populated due to its proximity to the capital Reykjavík . Here are z. B. the cities of Hafnarfjörður and Keflavík with the international Leifur Eiríksson airport , and several villages such as Njarðvík and Hafnir , which together with Keflavík form the municipality of Reykjanesbær , as well as the places Garður , Sandgerði and Grindavík .
Hallgrímur Pétursson as pastor in Hvalsnes
Hallgrímur Pétursson , a famous psalmist, was a pastor in the hamlet of Hvalsnes in the 17th century . In the cemetery you can still see his daughter's tombstone with a poem by the master.
Sights include the bird paradises at the very tip of the headland.
Knowledge Article on volcanism and plate displacement on Reykjanesskagi
- Amy E. Clifton, ea: Surface effects of triggered fault slip on Reykjanes Peninsula, SW Iceland , tectonophysics , Vol. 369, Iss. 3-4, July 2003, 145-54; doi : 10.1016 / S0040-1951 (09) 00201-4 (abstract, English)
- Agust Gudmundsson: Geometry, formation and development of tectonic fractures on the Reykjanes Peninsula, southwest Iceland , Nordic Volcanological Inst., Reykjavík 1986 (ScienceDirect, Abstract, English)
- R. Sigurbjörnsson et al. a., Comparative study of uniform hazard spectra derived using ground motion estimation models: A case study. The 14th World Conference on Earthquake Engineering, Oct. 12-17, 2008, Beijing, China, 14WCEE Paper 07-0099 (earthquake hazard assessment models on Reykjanes) (abstract, English)
- S. ÓLAFSSON, R. SIGBJÖRNSSON ATTENUATION OF STRONG GROUND MOTION IN SHALLOW EARTHQUAKES 13th World Conference on Earthquake Engineering Vancouver, BC, Canada August 1-6, 2004 Paper No. 1616
- M Keiding, ea: accumulation Strain along at oblique plate boundary: the Reykjanes Peninsula, southwest Iceland , Geophysical Journal International ; Vol. 172, Iss. 2, 861-72, Feb. 2008; doi : 10.1111 / j.1365-246X.2007.03655.x (Abstract, English) (Tensions at the plate boundaries on Reykjanes)
- Sigurlaug Hjaltadóttir: Use of relatively located microearthquakes to map fault patterns and estimate the thickness of the brittle crust in Southwest-Iceland , IMO, Skýrsla VÍ 2010-003 (English; PDF; 7.8 MB)
- M. Ómarsdóttir: Reykjanesskagi: Nátúrusaga og eldvbod. Háskóli Íslands, Reykjavík, 2007 (On the volcanic systems on Reykjanesskagi) (PDF file, 729 K; Icelandic)
- Ferlir (To the volcanoes on Reykjanes, largely based on M. Ómarsdóttir) (Icelandic)
- Kristján Sæmundsson: "General structure and volcanism of Reykjanes peninsula", ISOR, 2010 (English)
- cf. Thor Thordarson, Armann Hoskuldsson: Iceland. Classic Geology in Europe 3. Harpenden 2002, p. 64
- cf. z. B. http://www-new.grindavik.is/?i=2&s=53&ss=289&sss=297 Accessed January 9, 2011
- Thor Thordarson, Armann Hoskuldsson: Iceland. Classic Geology in Europe 3. Harpenden 2002, p. 63
- Thor Thordarson, ibid., P. 64
- Thor Thordarson, ibid., P. 63
- Thor Thordarson, ibid., P. 59f.
- http://www.volcano.si.edu/volcano.cfm?vn=371030&vtab=Eruptions Accessed: February 28, 2011
- see: Þorleifur Einarsson: Geology of Iceland. Rocks and Landscape. Reykjavík (Mál og menning) 1994, p. 63
- Reykjanes and Svartsengi are seen as the same system in: Thor Thordarson, Armann Hoskuldsson: Iceland. Geology of Europe 3. Harpenden 2002, p. 14
- Likewise in: Global Volcanism Program, Smithsonian Inst .; Access: 09.20.2011 (English)
- cf. z. B. Ari Trausti Guðmundsson: Living Earth. Facets of the geology of Iceland. Reykjavík (Mál og menning) 2007, p. 191.
- Thor Thordarson, ibid., P. 65
- Mega-drilling in Iceland: researchers tap volcano , Sputnik February 2, 2017
- Ari Trausti Guðmundsson, Pétur Þorleifsson: Íslensk fjöll. Gönguleiðir á 151 tind. Reykjavík (Mál og menning) 2004, p. 156
- Thor Thordarson, ibid., P. 62
- Members of the Global Geopark Network. Global Geopark Networks, accessed May 1, 2017 .
- Íslandshandbókin. 1. bindi. 1989, p. 48.
- Íslandshandbókin. 1. bindi. 1989, p. 43.
- cf. Íslandshandbókin. 1. bindi. 1989, pp. 48 and 78