Английская Википедия:Geysir
Шаблон:Short description Шаблон:About Шаблон:Use dmy dates Шаблон:Infobox landform Geysir (Шаблон:IPA-is), sometimes known as The Great Geysir, is a geyser in south-western Iceland,Шаблон:Sfn that geological studies suggest started forming about 1150 CE.Шаблон:Sfn The English word geyser (a periodically spouting hot spring) derives from Geysir.Шаблон:Sfn The name Geysir itself is derived from the Icelandic verb geysa ("to go quickly forward").[1] Geysir lies in the Haukadalur valley on the slopes of Laugarfjall lava dome, which is also the home to Strokkur geyser about Шаблон:Convert to the south.Шаблон:Sfn The Strokkur geyser may be confused with it, and the geothermal field it is in is known usually as either, Geysir or Haukadalur.
Eruptions at Geysir can typically hurl boiling water up to Шаблон:Cvt in the air.Шаблон:Sfn However, eruptions are nowadays infrequent, and have in the past stopped altogether for many years at a time.Шаблон:Sfn
History
A geyser at the general site is described in a written source by Saxo Grammaticus,[1] as a mention in Gesta Danorum, his work finished about 1206 which was printed in 1514 as Danorum Regum heroumque Historiae.[2] However the oldest definitive accounts of the hot springs at Haukadalur in their present form, date back to 1294,Шаблон:Sfn in the chronicle “Oddaverjaannáll”,Шаблон:Sfn when earthquakes in the area caused significant changes in local neighbouring landscape, creating several new hot springs.Шаблон:Sfn Changes in the activity of Geysir and the surrounding geysers are strongly related to earthquake activity.Шаблон:Sfn In records dated 1630, the geysers erupted so violently that the valley around them trembled.Шаблон:Sfn The name "Geysir" was first mentioned in written sources in 1647;Шаблон:Sfn as unusual natural phenomena were of great interest during the Age of Enlightenment, the term became popular and has been used for similar hydrothermal features worldwide since then.
In 1809 and 1810 the eruptions were about every 30 hours and up to Шаблон:Cvt high.[1] In 1811 George Mackenzie a geologist, first proposed that expansion of steam in a subsurface cavity explained Geysir's activity.Шаблон:Sfn In 1845, it reached a height of Шаблон:Cvt.Шаблон:Citation needed In 1846, research on Geysir, and Iceland sponsored by the Danish Crown, by amongst others, the German chemist Robert Bunsen, resulted in a better general explanation of the mechanism of geyser activity which contributed significantly to the more refined models used today.Шаблон:Sfn[1] Measurements by Professor Bunsen in that year showed that Geysir was erupting Шаблон:Cvt high.
In 1882 an account of the first accurate survey (previous attempts were associated with instrument problems), noted that a booming sound warned or Geysir's eruptions, eruptions were about 6 hourly but often of only Шаблон:Cvt.Шаблон:Sfn
The records of recent centuries show that earthquakes have tended to revive the activity of Geysir, which then subsided again in the following years.Шаблон:Sfn Before 1896, Geysir was almost dormant.Шаблон:Sfn In that year an earthquake caused eruptions to begin again, occurring several times a day, lasting up to an hour and causing spouts of up to Шаблон:Cvt in height.Шаблон:Sfn In 1910, it was active every 30 minutes; by 1915, the time between the eruptions was as much as six hours, and in 1916, the eruptions all but ceased. In 1935, a man-made channel was dug through the silica rim around the edge of the geyser vent.Шаблон:Sfn This ditch caused a lowering of the water table and a revival in activity.Шаблон:Sfn Gradually this channel also became clogged with silica and eruptions again became rare.Шаблон:Sfn
In 1981, the ditch was cleared again and eruptions could be stimulated, on special occasions, by the addition of soap.Шаблон:Sfn Due to environmental concerns, soap was seldom added during the 1990s. During that time, Geysir seldom erupted. When it did erupt, it was spectacular, sending boiling water sometimes up to Шаблон:Convert into the air. On the Icelandic National Day, authorized government geologists would force an eruption. Further earthquakes in 2000 revived the geyser,Шаблон:Sfn and it reached 122 meters for two days.Шаблон:Citation needed, thus becoming one of the highest known geysers in history. (Waimangu Geyser in New Zealand typically erupted higher than this and up to Шаблон:Cvt high,[3] but stopped all activity around 1908.Шаблон:Sfn[4] Initially, Geysir eruptions were taking place on average eight times a day. By July 2003, this activity had again decreased to around three times per day. Large eruptions after this became so rare that one in 2016 was considered newsworthy.[5]
Geology
A current geological definition of a hot water geyser is "…a hot spring characterized by intermittent discharge of water ejected turbulently and accompanied by a vapor phase"Шаблон:Sfn which is a technical correction on historic definitions that mentions steam and a column in air.[1] Geysir is technically a hot water pool geyser rather than a cone geyser so much heat is lost to the atmosphere explaining why the maximum temperature in its conduit is several meters below the top of the water column rather than at the top like is the case with Old Faithful.Шаблон:Sfn Geysir's funnel like surface conduit has a diameter of between Шаблон:Convert and until a narrow constriction a depth of about Шаблон:Convert.Шаблон:Sfn In the conduit above Шаблон:Cvt the geyser has a temperature between Шаблон:Cvt and reaches higher temperatures of about Шаблон:Cvt below this.Шаблон:Sfn The conduit in this higher temperature region is more constricted and irregular than earlier studies could ascertain, and fracture related with potential for the boiling temperature to be reached.Шаблон:Sfn Below Шаблон:Cvt the conduit has several branches and cavities.Шаблон:Sfn As it is closer to sea level than most of the world's 1000 odd geysers the actual erupted water temperature is higher than most.Шаблон:Sfn
The Шаблон:Cvt in area Haukadalur volcanic system, that provides the heat,Шаблон:Sfn is mainly to the west of Geysir but has not been active volcanically for over 10,000 years.Шаблон:Sfn Geysir is on the eastern slopes of the rhyolitic Laugarfjall lava dome,Шаблон:Sfn but the hyaloclastite nature of the rock that the water erupts through, may be important in its fracture network.Шаблон:Sfn It is now known that the areas of thermal activity of the geothermal field align along microfractures that became seismologically active after the 2000 Iceland earthquakes.Шаблон:Sfn
The geothermal water source may be the southern Langjökull ice sheet, about Шаблон:Cvt to the north.Шаблон:Sfn
Research on the deposits of sinter, formed from the dissolved minerals in the hot water, shows that hot springs at the Geysir location have been active for approximately 10,000 years.Шаблон:Sfn However before Geysir became active as a definitive geyser the previous deposits were covered with tephra from Katla and Hekla and little sinter was deposited for about 2000 years.Шаблон:Sfn Once Geysir became active, precipitation of opal from the geothermal water lead to a siliceous sinter apron around the geyser.Шаблон:Sfn This has allowed formation of the modern geyser to be dated to about 1150 CE which accords with the history of written mention above.Шаблон:Sfn
Nearby Geysers
The nearby geyser Strokkur erupts much more frequently than Geysir, erupting to heights of up to Шаблон:Convert every few minutes.Шаблон:Sfn Strokkur was first described in 1789.[1] There is contrast in its lack of warning of eruption with the case of Geysir and evidence that the plumbing might not be totally independent.Шаблон:Sfn Strokkur's conduit has also been mapped in detail and is pipe shaped to Шаблон:Cvt, where it narrows before expanding into a cavity at about Шаблон:Cvt before narrowing again into a fracture configuration at about Шаблон:Cvt where temperatures become close to the boiling point.Шаблон:Sfn Strokkur's activity has also been affected by earthquakes, although to a lesser extent than the Great Geysir.Шаблон:Sfn Due to its eruption frequency, online photos and videos of Strokkur are regularly mislabelled as depicting Geysir. There are around thirty much smaller geysers and hot pools in the area, including one called Litli Geysir ('Little Geysir').Шаблон:Sfn Detailed thermal mapping of the geothermal field has revealed 364 distinct hot areas.Шаблон:Sfn
Descriptions of the Great Geysir and Strokkur have been given in many travel guides to Iceland published from the 18th century onwards. Together with Þingvellir and the Gullfoss waterfall, they are part of the Golden Circle, the most famous tourist route in the country.
Geysir was officially protected by the Ministry for the Environment and Natural Resources on 17 June 2020.[6]
Ownership of the area
Until 1894, the Geysir area was owned by a local farmers.[7] In that year the area was sold to James Craig (later Lord Craigavon), a whiskey distiller from Ulster and a future Prime Minister of Northern Ireland.[7][8] Initially, he erected large fences around the site and an entrance fee was charged for visitors wishing to view the geysers.[7] The following year, he gave the area as a present to a friend, E. Craig, who dropped the entrance fees. Later Craig's nephew Hugh Rogers inherited the site.[8] In 1935, he sold the site to film director Sigurður Jónasson who subsequently donated it to the Icelandic people in perpetuity,[7] although full public ownership of all routes of access did not take place until 2017.[8]
Gallery
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The erupting Great Geysir in summer 2009
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Litli Geysir erupting
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Geysir in 2014
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A forest near the Geysir
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Diagram of a theoretical structure for Geysir, from 1882
See also
References
Sources
- Шаблон:Cite book
- Шаблон:Cite journal
- Шаблон:Cite journal
- Шаблон:Cite journal
- Шаблон:Cite journal
- Шаблон:Cite report
- Шаблон:Cite journal
Further reading
- The Great Geysir, Helgi Torfason of the Icelandic National Energy Authority, 1985 (no ISBN, but book available from the Geysir tourist center).
External links
Шаблон:Commons category-inline
- Information and photos of Geysir and the geothermal area
- Photos: [1][2][3]
- Videos: Iceland Travel Journal by Keith Chan
- Шаблон:Cite gvp
- ↑ 1,0 1,1 1,2 1,3 1,4 1,5 Шаблон:Cite EB1911
- ↑ Шаблон:Cite EB9
- ↑ Шаблон:Cite encyclopaedia
- ↑ Glennon, J Allan "World Geyser Fields" Шаблон:Webarchive Retrieved on 2008-04-04
- ↑ Шаблон:Cite news
- ↑ Шаблон:Cite news
- ↑ 7,0 7,1 7,2 7,3 Шаблон:Cite news
- ↑ 8,0 8,1 8,2 Шаблон:Cite news
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