Английская Википедия:Hengill

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Шаблон:Short description Шаблон:Infobox mountain Hengill (Шаблон:IPA-is) is a volcanic table mountain situated in the south-west of Iceland, to the south of Þingvellir.

The volcano is still active, as evidenced by its numerous hot springs and fumaroles, but the last eruption occurred approximately 2,000 years ago, before the settlement of Iceland.

Geography

The mountain is south of Lake Thingvallavatn (Þingvallavatn in Icelandic), south-west of the Nesjavellir geothermal area, south of Þingvellir National Park and is the most prominent part of a volcanic region that extends to the coast.[1] South of the mountain towards the coast is the Hellisheiði geothermal area to its south-west, and the town of Hveragerði on Iceland's main ringroad, Route 1 about Шаблон:Cvt east of Reykjavík.[1] At the coast is the port of Þorlákshöfn.[1]

Файл:Reykjanes volcanic systems.png
Map of the Reykjanes volcanic belt with 6) Hengill volcanic system
Файл:Hengladir.jpg
Overlooking the Hengladalir Шаблон:IPA-is valleys to the east of Hengill
Файл:Spring in Hengill, Iceland.jpg
A hot spring at the base of the Hengladalir valleys
A hot spring at the base of the Hengladalir valleys
A hot spring at the base of the Hengladalir valleys

Geology

The mountain is part of the Шаблон:Cvt long Hengill volcanic system,Шаблон:SnfШаблон:Snf which is part of the Reykjanes volcanic belt, and is a hyaloclastite massif of tuyas and tindars.Шаблон:Snf The dominant lava in the Hengill volcanic system is tholeiitic basalt,Шаблон:Snf but andesite and about Шаблон:Cvt rhyolite occur within the central mountain.Шаблон:Snf The largest lava shield covers about Шаблон:Cvt.Шаблон:Snf Four small lava shields are picrite basalt and one lava shield contains about Шаблон:Cvtof olivine tholeiite.Шаблон:Snf It is located at the intersection with two other tectonic volcanic systems, the West volcanic zone of Iceland and South Iceland seismic zone,Шаблон:SnfШаблон:Snf and is co-located to the plate boundary between the North American, Eurasian and Hreppar plates. This intersection is called the Hengill triple junction.Шаблон:Snf

Hveragerdi to the south is an volcano in the volcanic system that became extinct 300,000 years ago, but still has significant seismic activity.Шаблон:Snf It can be regarded as a predecessor volcano.Шаблон:Snf This seismic activity is significant not only because of human impact but also because the earthquakes are grouped along faults striking north–south or east–west, but not north to north-east, as might be supposed based on the surface geological structure and that the rift zone is deep as Шаблон:Cvt locally.Шаблон:Snf The earthquake distribution has been interpreted to have defined the heat source of the Hengill volcano.Шаблон:Snf

Extending to the north-east from the central volcano is a fissure swarm with a number of tindars associated with an asymmetrical graben.Шаблон:Snf Lake Thingvallavatn, occupies the proximal graben, and has at its southern end lava flows from the mountain and has hosted explosive eruptions historically. Amongst the faults on the north-west side of the graben is the Almannagjá chasm which extends from the northern shore of Lake Thingvallavatn.Шаблон:Snf

Towards the south-east from the mountain towards the sea is a lava covered plateau whose height is about Шаблон:Cvt with scattered higher tindars and tuyas.Шаблон:Snf

During the Holocene volcanic eruptions in the zone have been predominantly effusive and basaltic with minor tephra production. Erupted lava volumes have ranged from Шаблон:Cvt.Шаблон:Snf

Hengill area recent tectonic history
Date Event Comment
2008 CE Earthquake No loss of life but 50% property damage in Ölfus regionШаблон:Snf
1789 CE Subsurface dyke intrusion Dyke injection later identifiedШаблон:Snf
1000 CE Adjacent volcanic system eruption Fissure west of Hengill, in the Brennisteinsfjöll volcanic system.Шаблон:Snf This eruption was at the time of a meeting of the Icelandic parliament at Thingvellir.[2]
150±75 CE Eruption Along a fissure length of Шаблон:Cvt and about Шаблон:Cvt lava eruptedШаблон:Snf. Included phreatomagmatic eruption from lake Thingvallavatn.Шаблон:Snf[2]
80±75 BCE Eruption [2]
1730±50 BCE Eruption [2]
~3250 BCE Eruption [2]
~3750 BCE Eruption Along a fissure length of Шаблон:Cvt and about Шаблон:Cvt lava eruptedШаблон:Snf[2]
~5000 BCE Eruption [2]
~5550±500 BCE Eruption Not well datedШаблон:Snf[2]
~7100 BCE Eruption [2]
~7300 BCE Eruption [2]
~7550 BCE Eruption [2]
~8200 BCE Eruption Шаблон:Snf[2]
~8250 BCE Eruption [2]
~8350 BCE Eruption [2]

Risk

The official view of the volcanic hazard is that it is confined to a radius of Шаблон:Cvt and is related to lava flows, plugging of geothermal boreholes by lava, volcano-tectonic faulting and volcanic gas pollution.Шаблон:Snf [lower-alpha 1]

Geothermal resources

There are three associated geothermal areas related to the high amount of fissuring in the Hengill volcanic system producing high water subsurface permeability.Шаблон:Snf These areas include Iceland’s second largest geothermal field which now is an important source of energy for the south of the country.Шаблон:Snf The three areas are:

  1. Nesjavellir geothermal system, which is captured at the Nesjavellir power station near the western shore of the lake Þingvallavatn
  2. Hellisheiði, which has the largest power station in Iceland, Hellisheiði power station, approximately Шаблон:Cvt south-west of Nesjavelli. Both stations are operated by Orkuveita Reykjavíkur (Reykjavik Energy).
  3. Hveragerdi, whose hydrothermal waters have been used for greenhouse heating.

The area with its mountains and hot springs is well suited for hiking and there are a lot of hiking trails. The town of Hveragerði with its multitude of hot springs is also part of the Hengill area.

Culture

Some folk tales are connected to the region.[3] For example, in a folk tale collected and published by Jón Árnason in 1862, a young farmer is said to have killed the sleeping troll woman Jóra Шаблон:IPA-is while she lay in wait for innocent wanderers or horsemen on the trail over Dyrafjöll Шаблон:IPA-is north of Hengill.[4] In another folk tale, according to some people, a woman's body found in the area was believed to be that of Halla, the wife of the famous Icelandic outlaw Fjalla-Eyvindur.[4]

See also

Notes

Шаблон:Reflist

References

Шаблон:Reflist

Sources

External links

Шаблон:Volcanoes of Iceland Шаблон:Authority control

Партнерские ресурсы
Криптовалюты
Магазины
Хостинг
Разное

  1. ↑ 1,0 1,1 1,2 Ошибка цитирования Неверный тег <ref>; для сносок LI не указан текст
  2. ↑ 2,00 2,01 2,02 2,03 2,04 2,05 2,06 2,07 2,08 2,09 2,10 2,11 2,12 2,13 Ошибка цитирования Неверный тег <ref>; для сносок gvp не указан текст
  3. ↑ Шаблон:Cite web
  4. ↑ 4,0 4,1 Шаблон:Cite book


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