View source for Askja

{{Short description|Volcano in Iceland}}
{{about|the volcano|the building in Reykjavík|Askja (building)}}
{{Infobox mountain
 | name            = Askja
 | image           = Askja.jpg
 | image_caption   = Askja caldera in 1984
 | elevation_m     = 1516
 | elevation_ref   = <ref name=otm>{{cite opentopomap|Askja|65.01114|-16.73544|2023-06-15}}</ref>
 | prominence_m    = 
 | prominence_ref  = 
 | range           = [[Dyngjufjöll]]
 | listing         = [[List of volcanoes in Iceland|Volcanoes of Iceland]]
 | location        = [[Iceland]]
 | map             = Iceland
 | map_caption     = 
 | map_size        = 
 | label_position  = right
 | coordinates     = {{coord|65.033|N|16.783|W|type:mountain_scale:100000|format=dms|display=inline,title}}
 | coordinates_ref = <ref name=gvp>{{cite gvp|vn=373060|title=Askja|access-date=2024-06-26}}</ref>
 | type            = [[caldera]]
 | age             = 
 | last_eruption   = October to December 1961<ref name=gvp/>
 | first_ascent    = 
 | easiest_route   = 
 | fetchwikidata   = ALL
 | image_map       = {{maplink|frame=yes|frame-align=center|frame-width=300|frame-height=500|frame-long=-16.8|frame-lat=65.0|zoom=7|raw=[{{Wikipedia:Map data/Grímsvötn}},{{Wikipedia:Map data/Askja}},{{Wikipedia:Map data/Öræfi volcanic belt}},{{Wikipedia:Map data/Hofsjökull}},{{Wikipedia:Map data/Katla}},{{Wikipedia:Map data/Snæfellsnes volcanic belt}},{{Wikipedia:Map data/Hengill}}]
 | text              = Geological features near the Dyngjufjöll (Askja) central volcano and Askja volcanic system (red outlines). {{Wikipedia:Map data/Askja/key}}
}}
}}
[[File:Viti geothermal lake at Askja.jpg|thumb|right|300px|Víti geothermal lake at Askja]]
[[File:Island Askja.jpg|thumb|right|300px|Askja and Víti (in the foreground)]]

'''Askja''' ({{IPA|is|ˈasca||Askja_pronunciation_edit_9_27_2014.ogg}}) is an [[active volcano]] situated in a remote part of the [[Highlands of Iceland|central highlands]] of [[Iceland]]. The name Askja refers to a complex of nested [[caldera]]s within the surrounding [[Dyngjufjöll]] {{IPA|is|ˈtiɲcʏˌfjœtl̥|}} mountains, which rise to {{convert|1514|m|0|abbr=on}}, ''askja'' meaning ''box'' or ''caldera'' in Icelandic.<ref>See e.g.: Stóra Tölvuorðabókin. Úfgáfa 6.0</ref>

== Geography ==
The Askja central volcano is {{cvt|20|km}} in diameter and is associated with the '''Askja volcanic system''' which has a {{cvt|190|km}} long fissure swarm that extends north from beneath the [[Vatnajökull]] glacier towards the north coast of Iceland.<ref name =CIV>{{cite web|url =https://icelandicvolcanoes.is/?volcano=ASK|title= Catalogue of Icelandic Volcanoes:Askja Alternative name: Askja-Dyngjufjöll, Askja-Hrúthálsar|first1 =Thor|last1 =Thordarson|first2 = Margaret|last2=Hartley|year =2021}}</ref> The Hrúthálsar area which is {{cvt|20|-|30|km}} to the north-east is now usually regarded as part of the system.<ref name =CIV/>

The outer caldera of Askja, representing a prehistoric eruption, is about {{cvt|50|km2}} in area, and there is evidence of other later caldera-forming events within it. These include the main summit caldera, that is about {{cvt|8|km}} in diameter, to its north-east the {{cvt|4|km}} diameter Kollur caldera, and the 1875 Öskjuvatn caldera with a diameter of about {{cvt|5|km}}.  The main crater floor lies at about {{cvt|1100|m|ft}}.<ref name =CIV/>

The central volcano region is only accessible for a few months of the year. Being situated in the [[rain shadow]] to the northeast of the [[Vatnajökull]] [[glacier]], the area receives only about {{cvt|450|mm|in}} of [[rain]]fall annually.

=== NASA ===
The area was used by [[NASA]] during training for the [[Apollo program]] to prepare astronauts for the lunar missions. Their main objective in Askja was to study geology. [[The Astronaut Monument]] in [[Húsavík]] lists the 32 astronauts who participated.<ref>{{Cite web|title = Apollo astronauts revisit training area in Iceland and explore a new lava flow - The Exploration Museum|url = http://www.explorationmuseum.com/2015/07/astronauts-revisit-training-area-and-explore-a-new-lava-flow/|website = www.explorationmuseum.com|access-date = 2015-08-09|archive-date = 2019-04-02|archive-url = https://web.archive.org/web/20190402042808/http://www.explorationmuseum.com/2015/07/astronauts-revisit-training-area-and-explore-a-new-lava-flow/}}</ref><ref>{{Cite web|title = Barnabörn Armstrongs afhjúpuðu minnisvarða|url = http://www.mbl.is/frettir/innlent/2015/07/15/barnaborn_armstrongs_afhjupudu_minnisvarda/|access-date = 2015-08-09}}</ref>

== Eruptions ==
Most eruptions are small, basaltic and effusive.<ref name =CIV/>  There have been at least 175 eruptions from the Askja system in the last 7200 years.<ref name=Hartley2016/>

=== 1961 ===
The last eruption of Askja was between 26 October and 5 December 1961 near the northern rim of the caldera.<ref name=gvp/> It produced the {{cvt|0.1|km3}} [[basalt]]ic Vikrahraun lava flow and also near the caldera another local permafrost layer under the {{cvt|0.004|km3}} of tephra.<ref name=Shoemaker2024/><ref name =CIV/>

=== 1875 ===
Askja was virtually unknown until a large 17 hour [[Sub-plinian eruptions|subplinian eruption]] which started on March 28, 1875.<ref name=Büntgen2024>{{cite journal|last1 =Büntgen|first1 =U.|last2 =Eggertsson|first2 =O.|last3 =Oppenheimer|first3 =C.|year =2024|title= Braided motivations for Iceland's first wave of mass emigration to North America after the 1875 Askja eruption|journal =Regional Environmental Change|volume =24|issue =2|page =48|doi =10.1007/s10113-024-02215-6|bibcode =2024REnvC..24...48B|doi-access=free}}</ref> The volcanic system had been active since 1 January 1875.<ref name=gvp/> This was followed by the devastating [[rhyolitic]] phreatoplinian explosion on March 29, 1875,<ref name =CIV/><ref>{{Cite journal |last1=Hartley |first1=Margaret E. |last2=Thordarson |first2=Thor |date=2013-07-29 |title=The 1874-1876 volcano-tectonic episode at Askja, North Iceland: Lateral flow revisited |journal=Geochemistry, Geophysics, Geosystems |volume=14 |issue=7 |pages=2286–2309 |doi=10.1002/ggge.20151 |bibcode=2013GGG....14.2286H |s2cid=53587010 |issn=1525-2027|doi-access=free }}</ref> which erupted {{cvt|0.33|km3}} [[dense-rock equivalent]].<ref name=Shoemaker2024>{{cite journal|last1 =Shoemaker|first1 =E.S.|last2 =Baker|first2 =D.M.H.|last3 =Richardson|first3 =J.A.|last4 =Carter|first4 =L.M.|author4-link=Lynn Carter|last5 = Scheidt|first5 =S.P.|last6 =Whelley|first6 =P.L.|last7 =Young|first7 =K.E.|year =2024|title =Mapping ice buried by the 1875 and 1961 tephra of Askja Volcano, Northern Iceland using ground‐penetrating radar: Implications for Askja Caldera as a geophysical testbed for in situ resource utilization|journal =Journal of Geophysical Research: Planets|volume =129|issue =4|article-number =e2023JE007834|doi =10.1029/2023JE007834|doi-access =free}}</ref>  The eruption finished on 17 October 1875.<ref name=gvp/> Locally around the caldera this ash fall on snow cover has resulted in the formation of a layer of permafrost ice.<ref name=Shoemaker2024/> Especially in the [[Eastfjords]] of Iceland, the ashfall was heavy enough to poison the land and kill livestock. Ash more than 1&nbsp;cm in thickness covered {{cvt|5000|km2}} and the total population in Iceland of sheep declined by 2% and cattle by 6.2% between 1874 and 1876.<ref name=Büntgen2024/> At least 16 farms were abandoned in 1876.<ref name=Büntgen2024/> Ash, or [[tephra]] from this eruption was wind-blown to [[Norway]], [[Sweden]], [[Germany]] and [[Poland]].<ref name=Shoemaker2024/> The eruption triggered a spike in [[emigration]] from Iceland but not as much as the Grímsvötn eruptions in the 1880s.<ref name=Büntgen2024/> Between February and October 1875 about {{cvt|60|km}} north of the Askja central volcano there were episodic [[basalt]]ic fissure eruptions, which erupted a comparable volume of magma to the explosive phase.<ref name=Büntgen2024/>  The eruption had no direct effect on regional or Northern Hemisphere vegetation and climate.<ref name=Büntgen2024/>

=== Early Holocene ===
Another less well-known large rhyolitic eruption, called Askja-S (Skolli), occurred in the early [[Holocene]], 10,824 ± 97 years {{abbr|BP|before 1950}}.<ref name =CIV/><ref name=Kearney2018>{{cite journal|last1 =Kearney|first1 =R.|last2 =Albert|first2 =P.G.|last3 =Staff|first3 =R.A.|last4 =Pál|first4 =I.|last5 =Veres|first5 =D.|last6 =Magyari|first6 =E.|last7 =Ramsey|first7 =C.B.|year =2018|title =Ultra-distal fine ash occurrences of the Icelandic Askja-S Plinian eruption deposits in Southern Carpathian lakes: New age constraints on a continental scale tephrostratigraphic marker|journal =Quaternary Science Reviews|volume =188|pages =174–182|doi =10.1016/j.quascirev.2018.03.035|bibcode =2018QSRv..188..174K}}</ref> [[Tephra]] from this eruption has been found in south-east [[Sweden]], [[Northern Ireland]] and north [[Norway]] and recently as far south as [[Romania]], which makes it one of the most far-travelled Icelandic tephras.<ref name=Kearney2018/>

=== Summary ===
{| class="wikitable sortable" width=50%
|+ List of Recent Eruptions
|-
! data-sort-type="number" width=95px | Start Date<ref name=gvp/>
! data-sort-type="number" width=95px | End Date<ref name=gvp/>
! width=70px | VEI<ref name=gvp/>
! Scale<ref name=CIV/>
! width=70px | Tephra volume<br/>(km<sup>3</sup>)<ref name=CIV/>
! class="unsortable"| Comments
|-
| align="center"| {{dts|October 26, 1961}}
| align="center"| {{dts|December 5, 1961}}
! style="background-color: #FD0;" | 2 
| align="center"| Small
| align="center"| 0.004
| 
|-
| align="center"| {{dts|December 19, 1938}}
| {{unknown}}
! style="background-color: #FD0;" | 2 
| align="center"| Small
| {{unknown}}
|
|-
| align="center"| {{dts|July 15, 1926}}
| align="center"| 
! style="background-color: #FD0;" | 2 
| align="center"| Moderate
| {{unknown}}
| Lasted about 45 days, Thorvaldshraun lava<ref name=Hartley2016>{{cite journal|last1 =Hartley|first1 =M.E.|last2 =Thordarson|first2 =T. |last3 =de Joux|first3 =A.|year =2016|title =Postglacial eruptive history of the Askja region, North Iceland|journal =Bulletin of Volcanology|volume =78|pages =1–18|doi =10.1007/s00445-016-1022-7|bibcode =2016BVol...78...28H|doi-access=free}}</ref>
|-
| align="center"| {{dts|1924}}
| {{unknown}}
! style="background-color: #FF0;" | 0 
| align="center"| Small
| {{unknown}}
| 
|-
| align="center"| {{dts|January 15, 1923}}
| align="center"|
! style="background-color: #FF0;" | 0
| align="center"| Small
| {{unknown}}
| Lasted about 45 days
|-
| align="center"| {{dts|November, 1922}}
| {{unknown}}
! style="background-color: #FF0;" | 0 
| align="center"| Small
| {{unknown}}
| 
|-
| align="center"| {{dts|March, 1921}}
| {{unknown}}
! style="background-color: #FF0;" | 0
| align="center"| Small
| {{unknown}}
| 
|-
| align="center"| {{dts|1919}}
| {{unknown}}
! style="background-color: #FD0;" | 2 
| align="center"| Small
| {{unknown}}
|
|-
| align="center"| {{dts|January 1, 1875}}
| align="center"| {{dts|October 17, 1875}}
! style="background-color: #F60;" | 5 
| align="center"| Major
| align="center"| 1.8
| Lava flows mainly south and north-east of Öskjuvatn caldera<ref name=Hartley2016/>
|-
| align="center"| {{dts|1797}}
| {{unknown}}
! style="background-color: #FF0;" | 0
| align="center"| Small
| {{unknown}}
| Lava flow on west caldera margin dated as to before 1873 by tephra studies<ref name=Hartley2016/>
|-
| align="center"| {{dts|1717}}
| {{unknown}}
| -
| align="center"| Small
| {{unknown}}
| Older than 1717 from tephra studies with lava flows on north-east caldera margin<ref name=Hartley2016/>
|-
| align="center"| {{dts|1619}}
| {{unknown}}
| -
| align="center"| Small
| {{unknown}}
| Older than 1619 from tephra studies with lava flows on north caldera margin<ref name=Hartley2016/>
|-
| align="center"| {{dts|1510}}
| {{unknown}}
| -
| align="center"| Small
| {{unknown}}
| Older than 1510 from tephra studies with lava flows to west caldera margin<ref name=Hartley2016/>
|-
| align="center"| {{dts|1477}}
| {{unknown}}
| -
| align="center"| Small
| {{unknown}}
| Older than 1477 from tephra studies with lava flows around caldera margin<ref name=Hartley2016/>
|-
| align="center"| {{dts|1300}}
| {{unknown}}
! style="background-color: #FE0;" | 1 
| align="center"| Small
| {{unknown}}
| Older than 1341 from tephra studies with lava flows to north-east<ref name=Hartley2016/>
|-
| align="center"| {{dts|1158}}
| {{unknown}}
| -
| align="center"| -
| {{unknown}}
| Older than 1158 from tephra studies with lava flows to north-east 
<ref name=Hartley2016/>
|- 
| align="center"| {{dts|1104}}
| {{unknown}}
| - 
| align="center"| -
| {{unknown}}
| Older than 1104 from tephra studies with lava flows to immediate north-east of caldera<ref name=Hartley2016/>
|- 
| align="center"| {{dts|871}}
| {{unknown}}
| - 
| align="center"| -
| {{unknown}}
| Older than 871 from tephra studies with lava flow to south-east of caldera<ref name=Hartley2016/> 
|- 
| align="center"| 1250 ± 300 BCE
| {{unknown}}
! style="background-color: #FF0;" | 0 
| align="center"| Major
| {{unknown}}
| Older than 1045 BC from tephra studies with large lava fields north and south of caldera<ref name=Hartley2016/> 
|-
| align="center"| 2050 ± 500 BCE
| {{unknown}}
! style="background-color: #FF0;" | 0 
| align="center"| Small
| {{unknown}}
| Older than 2285 BC from tephra studies<ref name=Hartley2016/>
|-
| align="center"| 3750 BCE
| {{unknown}}
| -
| align="center"| -
| {{unknown}}
| Basalt tephra A5700 from Torfdalsvatn<ref>{{cite journal|last1 =Harning|first1 =D.J.|last2 =Florian|first2 =C.R.|last3 =Geirsdóttir|first3 =Á.|last4 =Thordarson|first4 =T.|last5 =Miller|first5 = G.H.|last6 =Axford|first6 =Y.|last7 =Ólafsdóttir|first7 =S.|year =2024|title =High-resolution Holocene record from Torfdalsvatn, north Iceland, reveals natural and anthropogenic impacts on terrestrial and aquatic environments|journal =Climate of the Past Discussions|pages =1–41|doi =10.5194/cp-2024-26|doi-access =free}}</ref>
|-
| align="center"| 8874 ± 97 BCE 
| {{unknown}}
! style="background-color: #F80;" | 5 
| align="center"| Major
| {{unknown}}
| 1.5 ± 0.5 km3 DRE<ref name=Kearney2018/>
|}

=== Activity ===
In June 2010, Volcano expert Hazel Rymer said seismic activity was increasing at Askja.<ref>{{cite web|url=http://www.express.co.uk/posts/view/180291/Volcano-expert-warns-of-another-Icelandic-eruption|title=Volcano expert warns of another Icelandic eruption|author=Emma Pryer|work=Express.co.uk|access-date=7 October 2014|date=2010-06-10}}</ref> The increased earthquake activity was located to the northeast of the [[central volcano]], in the direction of [[Herðubreið]]. It was ruled out that any activity from [[Eyjafjallajökull]] was responsible for the increase in activity at Askja. The news came as scientists continue to watch [[Katla volcano|Katla]]. In early April 2012 it was noted that the lake in the caldera was totally clear of ice, which usually does not happen until in June or July in a normal year. It was believed that increased geothermal activity in the volcano is heating the lake. Travel in the area was restricted until further research could be carried out.<ref>{{cite web|url=http://icelandreview.com/icelandreview/daily_news/Photos_Iceless_Iceland_Volcano_Lake_Causes_Speculation_0_388867.news.aspx|title=Photos: Iceless Iceland Volcano Lake Causes Speculation|work=Iceland Review|access-date=7 October 2014|archive-date=2 July 2012|archive-url=https://web.archive.org/web/20120702104651/http://www.icelandreview.com/icelandreview/daily_news/Photos_Iceless_Iceland_Volcano_Lake_Causes_Speculation_0_388867.news.aspx}}</ref>

In early September 2021, GPS and Satellite data showed that an inflation at the rate of five cm per month, most likely attributed to magma intrusion, of the caldera had started in August.<ref>{{Cite web|url=https://www.vedur.is/um-vi/frettir/land-ris-vid-oskju?|title=Land rís við Öskju &#124; Fréttir}}</ref> An Article published on September 9 from the Icelandic Meteorological Office(IMO) stated the Aviation Color Code was upgraded from "Green" to "Yellow" due to the changes.<ref>{{Cite web|title=Uncertainty level declared for the ongoing uplift at Askja volcano {{!}} News|url=https://en.vedur.is/about-imo/news/headline-for-askja-item|access-date=2021-09-09|website=Icelandic Meteorological office|language=en}}</ref> The Article also says, "Next week IMO and the Institute of Earth Sciences (UÍ) will potentiate the monitoring network around Askja to allow a better coverage and surveillance of the volcano." On 9 November 2022 deformation data showed continuing magma accumulation at depth, with accumulated uplift of {{cvt|40|cm}} since August 2021.<ref name=gvp/>

== Öskjuvatn lake ==
[[Öskjuvatn]] is a large lake that fills much of the smaller caldera resulting from the 1875 eruption. Its surface lies about {{cvt|50|m}} below the level of the main caldera floor and covers about {{cvt|12|km2}}. When the lake originally formed it was warm, but today it is frozen over for most of the year.  [[Öskjuvatn]] is the second deepest lake in Iceland at {{cvt|220|m}} deep.<ref>{{cite web|url=http://icelandreview.com/icelandreview/daily_news/?cat_id=40540&ew_0_a_id=336191|title=Jökulsárlón now Iceland's deepest Lake|work=Iceland Review|access-date=7 October 2014|archive-url=https://web.archive.org/web/20120329071059/http://icelandreview.com/icelandreview/daily_news/?cat_id=40540&ew_0_a_id=336191|archive-date=29 March 2012}}</ref>

== Missing scientists ==
In 1907, the German scientists Walter von Knebel and Max Rudloff visited Askja to study the caldera. While exploring Öskjuvatn in a small boat, they disappeared without a trace. Von Knebel's fiancée Ina von Grumbkow led an expedition to search for them, but no indication of what happened to them was ever found. Recent observations on the effects of a landslide, on 21 July 2014, has led to renewed speculation that the scientists were killed by a similar sudden event, a massive wave similar to the one estimated to be {{convert|30|meters|abbr=off}} high seen in 2014.<ref>{{cite web|url=http://icelandreview.com/stuff/views/2014/08/15/old-askja-case-solved-esa|title=Old Askja Case Solved? (ESA)|work=Iceland Review|access-date=7 October 2014|archive-date=12 October 2014|archive-url=https://web.archive.org/web/20141012093228/http://icelandreview.com/stuff/views/2014/08/15/old-askja-case-solved-esa}}</ref>

== Social context of 1875 Askja eruption ==
<!--entire paragraph tries to be a summary of Büntgen et al 2024 which is a good secondary source so only a single reference--->
The eruption took place at a time that Iceland was newly self governing under Danish rule, with a strong nationalist element, had a large rural agricultural population, and needed the fodder ruined by the eruption to overwinter livestock, in an up to then, relatively prosperous farming area. Following local publicity of the plight of farming communities in May 1775, and a letter to [[The Times]] in July 1775, fund-raising efforts in the UK, Denmark, and Norway took place and relief supplies were organised. The combined donations helped many of the most affected and paid for fodder to help keep livestock alive over the winter of 1875/6. The emigration options were limited, as the possibility of organised self funded emigration from Iceland to Canada or Brazil only became possible in January 1873, and by the time of the eruption the experiences reported home of the emigrants were far from all being positive. Canada in particular successfully promoted itself and addressed partially the initial issues, with partially subsidised emigration that excluded deliberately the Icelandic poor, for multiple reasons both commercial and social. However the Iceland nationalist political movement tried to block emigration, even misrepresenting that its new Emigration Law made the Canadian plan impossible, when the law had yet to be ratified in Denmark. A deposit paid to the Danish Governor of Iceland and advertising emphasising the impact of the eruption eased the Canadian plan. While most emigration in 1876 was by Icelanders resident outside the areas most affected by the ash it did result in up to 10% of the population in those districts most affected, leaving Iceland.<ref name=Büntgen2024/>

== Sights and tourism in the area ==
[[File:Drekagil-pjt2.jpg|thumbnail|300px|Drekagil canyon]]
The Dyngjufjöll mountains which surround the Askja caldera, also contain the ''Drekagil'' {{IPA|is|ˈtrɛːkaˌcɪːl̥|}}, the canyon of dragons. Within {{cvt|25|km}} and {{cvt|41|km}} of Askja, are two other volcanic systems: [[Herðubreið]] and [[Kverkfjöll]].

Askja is a popular tourist destination. There are two mountain huts and a campsite at Dreki {{IPA|is|ˈtrɛːcɪ|}}, by Drekagil, which is about {{cvt|100|km}} by a 4x4 F-road, from the Icelandic ring-road. The road continues {{cvt|8|km}} up from Dreki into the Askja caldera. It is a walk of about {{cvt|2.5|km}} from the car park to Öskjuvatn and Víti {{IPA|is|ˈviːtɪ|}}. The roads are usually only open for about three to four months, from late June until early October.

== See also ==
* [[Geography of Iceland]]
* [[Iceland plume]]
* [[List of glaciers of Iceland]]
* [[List of lakes of Iceland]]
* [[List of rivers of Iceland]]
* [[Volcanism of Iceland]]
** [[List of volcanic eruptions in Iceland]]
** [[List of volcanoes in Iceland]]

== References ==
{{Reflist}}

== External links ==
* [https://icelandicvolcanoes.is/?volcano=ASK Askja] {{Webarchive|url=https://web.archive.org/web/20180121071657/http://icelandicvolcanoes.is/?volcano=ASK |date=2018-01-21 }} in the [[Catalogue of Icelandic Volcanoes]]

=== Photos and videos ===
{{Commons category}}
* [http://isafold.de/panorama/panorama.htm Panoramic views of Iceland, including Askja]
* [https://web.archive.org/web/20130821045535/http://www.islandsmyndir.is/html_skjol/halendid/Askja_Viti_04-10/index.html Askja & Víti 2004 – 2010. Picture Gallery from islandsmyndir.is]
* [https://web.archive.org/web/20040620150840/http://www.bildungsservice.at/faecher/geo/Staaten%20und%20Landschaften/Island/Island%202/Island%202000-0010%20-%20Askja%20-%20Kratersee%20V%C3%ADti.JPG Photo of Víti Crater]

=== Scientific papers ===
<!--this article was originally written without inline citation or tools to help others verify statements - this section has been retained as they are sources and although its a lot of work they cover most facts left not mentioned by secondary or tertiary sources as of June 2024---> 
* [https://web.archive.org/web/20080510153657/http://www.earthice.hi.is/page/ies_askja Earthice, Univ. of Iceland, description of Askja]
* [http://www.volcano.si.edu/world/volcano.cfm?vnum=1703-06=Askja Askja, Global Volcanism Program, Smithsonian Institution] {{Webarchive|url=https://web.archive.org/web/20190713123049/http://www.volcano.si.edu/world/volcano.cfm?vnum=1703-06=Askja |date=2019-07-13 }}
* [https://web.archive.org/web/20160304191842/http://www.raunvis.hi.is/~astahj/MSritgerd_ARH.pdf Asta R. Hjartadóttir (2008): ''The fissure swarm of the Askja central volcano'', Univ. of Iceland] (PDF)
* [http://www.open2.net/blogs/scitechnature/index.php/2009/11/19/title-4?blog=7 Rymer, Hazel: ''The case of the shrinking volcano'', 19.11.2009 (Blogpost of the geophysicist)]
* [https://docs.google.com/viewer?a=v&q=cache:1SXSrNIKOnUJ:notendur.hi.is/~heidi/Data/Heidi-publ08-10/Keyetal08-iavcei-iceland.pdf+askja&hl=en&pid=bl&srcid=ADGEESgGliB63b2nh- UP60q3hTuL0bQFayjWySe2pbcHXPDZorubx8kmqCf_1h8qfhNK96ufjwrE1OtY0T5jRPfGrBVxChdVBHFtgfgBfthdw5YCWuUAC2x89gg1TGjBR_hf8-1GoQtO&sig=AHIEtbTVxfbK9oIgvpHCLi7O2Yv8YudG7Q A. Key, e.a.: ''Crustal seismicity beneath Askja volcano reflecting plate tectonics and melt movement.'' (Zur Erdbebentätigkeit an der Askja)] (PDF, 31 KB)
* [http://onlinelibrary.wiley.com/doi/10.1111/j.1365-3121.2010.00948.x/abstract;jsessionid=0C2AE6DC8D372C56A21A91454935D28C.d03t03 Rymer, H., C. Locke, B. G. Ófeigsson, P. Einarsson, and E. Sturkell (2010):'' New mass increase beneath Askja volcano, Iceland – a precursor to renewed activity?'' Terra Nova, 22, 309–313. ] {{doi|10.1111/j.1365-3121.2010.00948.x}}
* [http://www.ajsonline.org/cgi/content/abstract/260/9/641 Sigurdur Thorarinsson, and G. E. Sigvaldason: ''The eruption in Askja 1961, a preliminary report.'' American Journal of Science, Vol. 260, November 1962, P.641-651];  {{doi|10.2475/ajs.260.9.641}} (Abstract)
* [https://web.archive.org/web/20120612090102/https://notendur.hi.is/~heidi/Data/Herdu-Askja-literature/Tryggvason89.pdf Eysteinn Tryggvason: ''Ground deformation in Askja, Iceland: its source and possible relation to flow of the mantle plume'', Journal of Volcanology and Geothermal Research, 39 (1989) 61–71 61] (PDF)
* [https://web.archive.org/web/20120612090255/https://notendur.hi.is/~heidi/Data/Herdu-Askja-literature/SturkellSigmundsson00.pdf Erik Sturkell, Freysteinn Sigmundsson: ''Continuous deflation of the Askja caldera, Iceland, during the 1983–1998 noneruptive period'', JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 105, NO. B11, PP. 25,671–25,684, 2000];  {{doi|10.1029/2000JB900178}} (PDF)
* [https://doi.org/10.1007%2Fs00445-009-0297-3 Heidi Soosalu, Janet Key, Robert S. White, Clare Knox, Páll Einarsson und Steinunn S. Jakobsdóttir: ''Lower-crustal earthquakes caused by magma movement beneath Askja volcano on the north Iceland rift'', Bulletin of Volcanology, Vol. 72, no. 1, 55–62];  {{doi|10.1007/s00445-009-0297-3}} (Springer-Link, Abstract)
* [http://webarchive.nationalarchives.gov.uk/20090402184322/http://gef.nerc.ac.uk/documents/publications/842.pdf Heidi Soosalu, e.a.: ''Askja 2007 – Scientific Project.''] (PDF)
* [http://oro.open.ac.uk/66/1/Rymer_5_-_Askja_short_paper.pdf Rymer, Hazel and Tryggvason, Eysteinn (1993): ''Gravity and elevation changes at Askja, Iceland.'' Bulletin of Volcanology, 55(5), pp. 362–371.] (PDF)
*{{cite journal|last1 =Shoemaker|first1 =E.S.|last2 =Baker|first2 =D.M.H.|last3 =Richardson|first3 =J.A.|last4 =Carter|first4 =L.M.|author4-link=Lynn Carter|last5 = Scheidt|first5 =S.P.|last6 =Whelley|first6 =P.L.|last7 =Young|first7 =K.E.|year =2024|title =Mapping ice buried by the 1875 and 1961 tephra of Askja Volcano, Northern Iceland using ground‐penetrating radar: Implications for Askja Caldera as a geophysical testbed for in situ resource utilization|journal =Journal of Geophysical Research: Planets|volume =129|issue =4|article-number =e2023JE007834|doi =10.1029/2023JE007834|doi-access =free}}
* {{cite journal|last1 =Büntgen|first1 =U.|last2 =Eggertsson|first2 =O.|last3 =Oppenheimer|first3 =C.|year =2024|title= Braided motivations for Iceland's first wave of mass emigration to North America after the 1875 Askja eruption|journal =Regional Environmental Change|volume =24|issue =2|page =48|doi =10.1007/s10113-024-02215-6|bibcode =2024REnvC..24...48B|doi-access=free}}

{{Volcanoes of Iceland}}

{{Authority control}}

[[Category:Highlands of Iceland]]
[[Category:Mountains of Iceland]]
[[Category:Stratovolcanoes of Iceland]]
[[Category:Active volcanoes]]
[[Category:VEI-5 volcanoes]]
[[Category:Volcanic crater lakes]]
[[Category:North Volcanic Zone of Iceland]]
[[Category:19th-century volcanic events]]
[[Category:One-thousanders of Iceland]]
[[Category:Volcanic systems of Iceland]]
[[Category:Calderas of Iceland]]
[[Category:Central volcanoes of Iceland]]