The Oddnýjarhnjúkur-Langjökull ( Langjökull ) volcanic system of Iceland last erupted about 3600 years ago and is associated with current geothermal activity. The area of its central volcano is at present under the second largest ice cap in Iceland.
18-547: Hveravellir ( Icelandic pronunciation: [ˈkʰvɛːraˌvɛtlɪr̥] ) is a geothermal field (high temperature field) of the Oddnýjarhnjúkur-Langjökull volcanic system [ˈɔtːˌniːjarˌn̥juːkʏr̥] - Icelandic pronunciation: [ˈlauŋkˌjœːkʏtl̥] in the north of the Langjökull glacier. Hveravellir geothermal area is a small nature reserve and a tourist centre located at 600 m (2,000 ft) at
36-638: A height of 1,066 m (3,497 ft) and to the north the Langjökull ice cap at 870 km (340 sq mi) in area and second in area in Iceland, covers its central volcano of Oddnýjarhnjúkur. The highest point within the Langjökull icecap is to its north east where the Baldjökull part of the ice cap covers a tuya of the same name with a height of 1,435 metres (4,708 ft). The geothermal area of Hveravellir with hot springs , fumaroles and mud pools
54-544: A volume of about 13 km (3.1 cu mi). It is sometimes considered a separate volcanic system with the southern fissures having erupted lavas with ages between 10,200 years and the most recent Thjófahraun lava field of the Oddnýjarhnjúkur-Langjökull volcanic system of 3600 years ago. The 7800 years BP Kjalhraun flow to the north-east has a similar area but covers only 11 km (2.6 cu mi) with its eastern portion broken up by faulting from
72-532: Is at the northern border of the large lava shield Kjalhraun [ˈcʰalˌr̥œyːn] . The main geothermal area covers around 2.5 km (0.97 sq mi). The hot springs are of various types, geysers , fumaroles , solfataras , boiling pits and warm springs with lower temperatures. The currently active geysers only have small irregular eruptions. Sinter and geyserite is prominent, forming low and wide domes around active or extinct geothermal centres. In Breiðimelur [ˈpreiːðɪˌmɛːlʏr̥] , north of
90-439: Is close to 25 km (6.0 cu mi) of ice. Hofsjökull has been modelled to lose all its ice in about 200 years from studies using data between 1980 and 2005. Run off into the draining rivers is modelled to increase by about 50% by 2100 before decreasing due to diminishing area of the ice caps. The subglacial volcano is a central volcano with a caldera . Beyond the central volcano are fissure systems which include to
108-501: Is the source of several rivers including the Þjórsá , Iceland's longest river. While all ice caps in Iceland have been losing volume since 1995, due to high precipitation in 2015 and low ablation during the previous cool summer, the Hofsjökull ice cap increased in mass, the first time in 20 years this had happened. Between 1989 and 2015, even allowing for that last years increase, the icecap had lost about 12% of its 1989 volume which
126-509: Is to the north east of the central volcano in the northern part of the fissure swarm which is dominated by Kjalhraun at 840 metres (2,760 ft). To the west is the Prestahnúkur volcanic system with the small ice cap of Eiríksjökull 21 km (8.1 sq mi) in area, and to the east of Langjökull is the Hofsjökull volcanic system with the large Hofsjökull ice cap and to its south
144-607: The Hofsjökull volcanic system . On the Kjalhraun flow's northern edge is the Hveravellir high-temperature geothermal field with an area of 2.5 km (0.97 sq mi). As part of the Western volcanic zone of Iceland which is a receding rift, and the north–western edge of the Hreppar microplate , the Oddnýjarhnjúkur-Langjökull volcanic system does not accommodate currently as much of
162-456: The Iceland hotspot to the east is believed to increase the magma supply. Hofsj%C3%B6kull Hofsjökull ( Icelandic : " temple glacier", Icelandic pronunciation: [ˈhɔfsˌjœːkʏtl̥] ) is the third largest ice cap in Iceland after Vatnajökull and Langjökull and covers the largest active central volcano in the country, which has the same name. It is situated in
180-587: The Kerlingarfjöll volcanic massif. A large tuya and composite volcano Hrútfell with a height of 1,396 m (4,580 ft) is located between Baldjökull and Kerlingarfjöll at the southern end of the Kjölur plateau between the two volcanic systems which is reached by the Kjalvegur road (F35) . Currently apart from the geothermal activity already mentioned at Geysir and Hveravellir there have been earthquake swarms to
198-430: The Kjölur mountain route between the glaciers Hofsjökull and Langjökull, in central Iceland. It is part of the Oddnýjarhnjúkur-Langjökull volcanic system. The place has been a popular resting place in highland travels since the age of settlement, 1100-1200 years ago. It is frequently mentioned in the old sagas, annals and folklore. Refuge huts have been situated there from the early beginning. The main geothermal activity
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#1732884273175216-503: The fissure system which is up to 20 km (12 mi) wide extends up to 100 km (62 mi) north. The Laugarfjall lava dome on the western side of the Haukadalur valley that houses the Geysir geothermal area with its geysers and other geothermal features is part of the southern fissure swarm. The shield volcano of Skjaldbreiður is prominent to the north of the rift valley with
234-445: The island. The geothermal field is a tourist attraction ; a bath can be taken in the pool created by damming the hot water stream in 1950. Hveravellir is a declared natural monument. Oddn%C3%BDjarhnj%C3%BAkur-Langj%C3%B6kull volcanic system The volcanic system is located north of Lake Thingvallavatn and its southern lava flows contribute to the floor of the Þingvellir rift valley central to Icelandic cultural history and
252-426: The main thermal area, there are several steam vents where people have baked black rye bread in the hot ground. A continuation of the thermal area can be traced several kilometers towards the north were several hot springs are found. The oldest description of Hveravellir dates back to 1752 when Icelandic travelers Eggert Ólafsson (1726–1768) and Bjarni Pálsson (1719–1779) described the field in their travel report on
270-715: The mutual movement of the North American Plate and Eurasian Plate as the volcanic zones to its south or east. The Western volcanic zone is an ultra-slow divergent spreading center, spreading at about 7 mm (0.28 in)/year at the Hengill triple junction at its south and with no spread where the Mid-Iceland belt which is the northern boundary of the Hreppar microplate meets the Western volcanic zone at Langjökull. The closeness of
288-437: The predominant lava being olivine tholeiite basalt . Only effusive eruptions have been identified. The Oddnýjarhnjúkur central volcano has caldera structures that have at their rim silicic hyaloclastite that formed during the ice age. The oldest deposits are about 800,000 years old. The Skjaldbreiður lava shield has three lava units deposited between 6000 and 9000 years BP , and covers 170 km (66 sq mi) with
306-614: The south-east of the Langjokull glacier and north of Hveravellir. While some of the fairly recently erupted Hallmundarhraun lava flow came from vents immediately adjacent to the north-west boundary of the system these eruptions are now assigned to the Prestahnúkur volcanic system. The Oddnýjarhnjúkur-Langjökull volcanic system is mountainous as it has ice age subglacially erupted tuyas and tindars up to 10 km (6.2 mi) long, with post glaciation lava shields and volcanic fissures with
324-478: The west of the Highlands of Iceland and north of the mountain range Kerlingarfjöll , between the two largest glaciers of Iceland. It covers an area of 830 km (320 sq mi), with the icecap top being 1,782 metres (5,846 ft), and bottom being at about 600 m (2,000 ft). There are other summits relating to the underlying volcano with two being at 1,765 m (5,791 ft). Hofsjökull
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