Öræfajökull

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Öræfajökull
Öræfi volcanic belt
(brown shading) is available on clicking the image to enable mouse-over.
Hvannadalshnúkur
, the highest peak of Öræfajökull.

Öræfajökull (Icelandic pronunciation:

Öræfi glacier' or 'wasteland glacier') is an ice-covered volcano in south-east Iceland. The largest active volcano and the highest peak in Iceland at 2,110 metres (6,920 ft), it lies within the Vatnajökull National Park
and is covered by part of the glacier.

The

Modern Icelandic: Hnappafellsjökull [ˈn̥ahpaˌfɛlsˌjœːkʏtl̥]; 'knobs mountain glacier').[4]
The current name, Öræfajökull, was eventually adopted after the 1362 eruption.

Description

Öræfajökull is located at the southern extremity of the

Hvannadalshnúkur
, the highest peak in Iceland at 2,110 metres (6,920 ft).

Geographically, Öræfajökull as the glacier, is considered part of Vatnajökull, and the area covered by glacier is within the boundary of Vatnajökull National Park. There are a number of outlet glaciers in the ice cap within the area of the central volcano which clockwise from north are: Breiðamerkurjökull, Fjallsjökull, Hrútárjökull, Bræðrajökull, Kviarjökull, Hólárjökull, Stórhöfðajökull, Gljúfursárjökull, Rótarfjallsjökull (which has a western branch called Kotárjökull), Grænafjallsjökull, Falljökull, Virkisjökull, Svinafellsjökull and Skaftafellsjökull.[5] While most of the outlet glaciers have reasonably clear catchments, not all do. Some of the icecap feeds directly into river catchments without a named glacier and this happens between the Hrútárjökull and Bræðrajökull, and the Virkisá river drains a number of glaciers between Rótarfjallsjökull and Svinafellsjökull (see map on this page).[5][6]: 144 

The summit caldera of this

Eastern volcanic zone.[7]
The presently active summit caldera may have a subcaldera within it.[6]: 146–148  Eruptions in this area are most likely to result in jökulhlaups that will produce floods at the outlets of the Kviarjökull and Virkisá catchments as these overlap the present caldera.[6]: 144  There is possibly an old caldera to the north of the current caldera and flank eruptions could produce jökulhlaup from other outlet glaciers.[6] The topographical map on this page can be enlarged to show this detail.

Activity

Öræfajökull has erupted twice in historical times, in 1362 and 1728. These were explosive silicic eruptions with bulk tephra volumes of 0.1–10.0 km3 (0.024–2.399 cu mi) and jökulhlaups occurred.

olivine basalt and both have been erupted in the Holocene.[2]

1362 eruption

In 1362, Knappafellsjökull erupted explosively, ejecting 10 cubic kilometres of

Öræfi. The name literally means 'an area without harbour,' but it took on a meaning of 'wasteland' in Icelandic, as the 1362 eruption had drastically altered the environment around the mountain.[9]
The volcano likewise took on the new name Öræfajökull.

1728 eruption

An eruption in August 1727–1728 was smaller than 1362, though floods are known to have caused three fatalities when the meltwater swept their farm away.[9]

1899 map of Öræfajökull from a nautical chart

2017 activity

Increased earthquake activity in the form of small tremors ranging from a depth of 1.5–10 km beneath the summit crater, began in August 2017 according to the Icelandic Meteorological Office.

The Aviation Colour Code of the United States was raised to yellow on 17 November 2017, after the appearance of an ice cauldron inside the main crater and increased geothermal activity under the glacier.[10]

2018 activity

The seismic and geothermal activity which began in August 2017 continued into 2018, but at reduced levels. On 4 May 2018, the Icelandic Meteorological Office lowered the Aviation Colour Code to green. [11]

Landslide

In 2013 due to paraglacial slope failure, a large landslide affecting an area of 1.7 km2 (0.66 sq mi) occurred, that deposited debris on the volcano's Svínafellsjökull outlet glacier.[12]

See also

References

  1. ^ "Hvannadalshnukur". Summitpost.com. Retrieved 9 August 2013
  2. ^ a b c d e Höskuldsson, Ármann (2019). "Catalogue of Icelandic Volcanoes:Öræfajökull". Retrieved 3 March 2024.
  3. ^ "Öræfajökull: Eruptive History". Global Volcanism Program. Smithsonian Institution. Retrieved 3 March 2024.
  4. ^ a b "History of Öræfajökull | VolcanoCafe".
  5. ^ a b "National Land Survey of Iceland-Mapviewer (Kortasja-Landmælingar Íslands)". Retrieved 6 March 2024.
  6. ^ a b c d Magnússon, E.; Pálsson, F.; Björnsson, H.; Guðmundsson, S. (2012). "Removing the ice cap of Öræfajökull central volcano, SE-Iceland: mapping and interpretation of bedrock topography, ice volumes, subglacial troughs and implications for hazards assessments". Jökull. 62: 131–150. Retrieved 4 March 2024.
  7. ^
    hdl:20.500.11815/1275
    .: Geological Background 
  8. ^ a b "About Öræfajökull | Vatnajokull National Park". Archived from the original on 2021-06-24. Retrieved 2021-06-19.
  9. ^ a b Ravilious, Kate (3 December 2017). "Terrawatch: the reawakening of Öræfajökull". The Guardian – via www.theguardian.com.
  10. ^ "A new ice-cauldron in Öræfajökull volcano | News". Icelandic Meteorological office.
  11. ^ "Öræfajökull: Activity Archives". Global Volcanism Program. Smithsonian Institution. Retrieved 26 August 2021.
  12. doi:10.1002/esp.5398
    .

External links
Road to Öræfajökull, approaching from the west, November 2007. Two spur glaciers can be seen: Skaftafellsjökull (left) and Svínafellsjökull (right).
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