Editing Geysir (section)

==History==
A geyser at the general site is described in a written source by [[Saxo Grammaticus]],<ref name=EB1911>{{Cite EB1911 |wstitle= Geyser |last= |first= |author-link= |volume= 11 |pages= 913-915 |short=1}}</ref> as a mention in [[Gesta Danorum]], his work finished about 1206 which was printed in 1514 as Danorum Regum heroumque Historiae.<ref>{{Cite EB9 |wstitle= Geysers |volume= X |pages=556-558 |short= 1}}</ref> However the oldest definitive accounts of the hot springs at Haukadalur in their present form, date back to 1294,{{sfn|Jones|Renaut|2021|loc=Age of Geysir}} in the chronicle “Oddaverjaannáll”,{{sfn|Jones|Renaut|2021|loc=Introduction}} when earthquakes in the area caused significant changes in local neighbouring landscape, creating several new hot springs.{{sfn|Pasvanoglu|1998|p=282}} Changes in the activity of Geysir and the surrounding geysers are strongly related to [[earthquake]] activity.{{sfn|Pasvanoglu|1998|p=282}} In records dated 1630, the geysers erupted so violently that the valley around them trembled.{{sfn|Pasvanoglu|1998|p=282}} The name "Geysir" was first mentioned in written sources in 1647;{{sfn|Jones|Renaut|2021|loc=Introduction}} 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.
[[File:BLAKE(1873) p06 The Great Geysir.jpg|thumb|upright|1873 drawing of Geysir]]
In 1809 and 1810 the eruptions were about every 30 hours and up to {{cvt|30|m}} high.<ref name=EB1911/> In 1811 [[Sir George Mackenzie, 7th Baronet|George Mackenzie]], a geologist, first proposed that expansion of steam in a subsurface cavity explained Geysir's activity.{{sfn|Hurwitz|Manga|2017|loc=4.1. Subsurface Processes}} In 1845, it reached a height of {{cvt|170|m}}.{{Citation needed|reason=This claim needs a reliable source; Bunsden works do not appear to validate - reliable source is likely to be in Danish or German giving scientific studies sponsored at the time.|date=February 2024}} In 1846, research on Geysir, and Iceland sponsored by the [[Christian VIII of Denmark|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.{{sfn|Pasvanoglu|1998|p=287}}<ref name=EB1911/> Measurements by Professor Bunsen in that year showed that Geysir was erupting {{cvt|45|-|54|m}} 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 {{cvt|5|ft}}.{{sfn|Peek|1882|p=132}}

The records of recent centuries show that earthquakes have tended to revive the activity of Geysir, which then subsided again in the following years.{{sfn|Walter|Jousset|Allahbakhshi|Witt|2020|loc=4.2. Implications}}  Before 1896, Geysir was almost dormant.{{sfn|Pasvanoglu|1998|p=282}} 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 {{cvt|70|-|80|m}} in height.{{sfn|Pasvanoglu|1998|p=286}} 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.{{sfn|Pasvanoglu|1998|p=282}} This [[ditch]] caused a lowering of the [[water table]] and a revival in activity.{{sfn|Pasvanoglu|1998|p=282}} Gradually this channel also became clogged with silica and eruptions again became rare.{{sfn|Pasvanoglu|1998|p=282}}

In 1981, the ditch was cleared again and eruptions could be stimulated, on special occasions, by the addition of [[soap]].{{sfn|Pasvanoglu|1998|p=282}} 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 {{convert|70|m}} into the air. On the [[Icelandic National Day]], authorized government geologists would force an eruption. Further earthquakes in 2000 revived the geyser,{{sfn|Stefánsson|Guðmundsson|Halldórsson|2000}} and it reached 122 meters for two days.{{Citation needed|reason=This claim needs a reliable source; see Talk.|date=July 2011}}, thus becoming one of the highest known geysers in history. [[Waimangu Geyser]] in [[New Zealand]] typically erupted higher than this, up to {{cvt|460|m}} high,<ref>{{cite encyclopaedia|first1 =C.|last1 =Stewart|title ='Hot springs, mud pools and geysers - Geysers', Te Ara - the Encyclopedia of New Zealand|url =https://www.TeAra.govt.nz/en/photograph/6497/waimangu-geyser-the-worlds-largest |access-date= 1 February 2024}}</ref> but it stopped all activity around 1908.{{sfn|Hurwitz|Manga|2017|loc=4.2. Surface Eruption}}<ref>Glennon, J Allan [http://www.uweb.ucsb.edu/~glennon/geysers/world.htm "World Geyser Fields"] {{webarchive|url=https://web.archive.org/web/20070630141427/http://www.uweb.ucsb.edu/~glennon/geysers/world.htm |date=2007-06-30 }} Retrieved on 2008-04-04</ref> 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.<ref>{{cite news|url=https://icelandmonitor.mbl.is/news/nature_and_travel/2016/02/21/rare_eruption_of_iceland_s_most_famous_hot_spring_g/|title=Rare eruption of Iceland's most famous hot spring Geysir|date =19 April 2016|archive-date=27 April 2016| archive-url=https://web.archive.org/web/20160427185308/https://icelandmonitor.mbl.is/news/nature_and_travel/2016/02/21/rare_eruption_of_iceland_s_most_famous_hot_spring_g/}}</ref>