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Askja

Photo of this volcano
  • Iceland
  • Iceland and Arctic Ocean
  • Stratovolcano
  • 1961 CE
  • Country
  • Volcanic Region
  • Primary Volcano Type
  • Last Known Eruption
  • 65.033°N
  • 16.783°W

  • 1080 m
    3543 ft

  • 373060
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number
Most Recent Weekly Report: 10 September-16 September 2014 Citation IconCite this Report

IMO had maintained the Aviation Colour Code for Askja at Yellow since 28 August due to elevated seismicity and localized deformation. On 11 September the Colour Code was reduced to Green when seismicity had diminished significantly.

Source: Icelandic Meteorological Office (IMO)

Weekly Reports - Index


2014: September


10 September-16 September 2014 Citation IconCite this Report

IMO had maintained the Aviation Colour Code for Askja at Yellow since 28 August due to elevated seismicity and localized deformation. On 11 September the Colour Code was reduced to Green when seismicity had diminished significantly.

Source: Icelandic Meteorological Office (IMO)


The Global Volcanism Program has no Bulletin Reports available for Askja.

This compilation of synonyms and subsidiary features may not be comprehensive. Features are organized into four major categories: Cones, Craters, Domes, and Thermal Features. Synonyms of features appear indented below the primary name. In some cases additional feature type, elevation, or location details are provided.

Eruptive History

There is data available for 14 Holocene eruptive periods.

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
1961 Oct 26 1961 Dec 5 ± 4 days Confirmed 2 Historical Observations North of Öskjuvatn lake (Vikraborgir)
1938 Dec 19 (?) Unknown Confirmed 2 Historical Observations South shore of Öskjuvatn lake
1926 Jul 15 ± 45 days Unknown Confirmed 2 Historical Observations South end of Öskjuvatn lake
1924 (?) Unknown Confirmed 0 Historical Observations South flank of Dyngjufjöll massif
1923 Jan 15 ± 45 days Unknown Confirmed 0 Historical Observations SE corner of Öskjuvatn Caldera
1922 Nov Unknown Confirmed 0 Historical Observations 1 km SW of Öskjuvatn Caldera
1921 Mar Unknown Confirmed 0 Historical Observations NE caldera wall, 0.6 km SE of Viti
1919 Unknown Confirmed 2 Historical Observations Dyngjufjöll
1875 Jan 1 1875 Oct 17 Confirmed 5 Historical Observations Öskjuvatn Caldera, Viti, Sveinagja
1797 (?) Unknown Confirmed 0 Historical Observations Holuhraun
1300 (?) Unknown Confirmed 1 Tephrochronology South of Dyngjufjöll Ytri
1250 BCE ± 300 years Unknown Confirmed 0 Tephrochronology Litladynga and Askja
2050 BCE ± 500 years Unknown Confirmed 0 Tephrochronology Flatadyngja, other areas NE of Dyngjufjöll
8910 BCE ± 200 years Unknown Confirmed 5 Radiocarbon (corrected) SE part of Askja caldera
Deformation History

There is data available for 3 deformation periods. Expand each entry for additional details.


Deformation during 2000 - 2009 [Subsidence; Observed by InSAR]

Start Date: 2000 Stop Date: 2009 Direction: Subsidence Method: InSAR
Magnitude: Unknown Spatial Extent: Unknown Latitude: Unknown Longitude: Unknown

Remarks: InSAR data from the Radarsat satellite shows that Askja continued subsiding from 2000 to 2009.

Figure (see Caption)

Average LOS velocity (mm/yr) over 9 years from the F1 (left) and F5 (right) frame. Incoherent white oval area is lake O?skjuvatn.

From: de Zeeuew-van Dalfsen et al. 2012.


Reference List: de Zeeuew-van Dalfsen et al. 2012.

Full References:

de Zeeuw-van Dalfsen, E., R. Pedersen, A. Hooper, and F. Sigmundsson,, 2012. Subsidence of Askja caldera 2000-2009: Modelling of deformation processes at an extensional plate boundary, constrained by time series InSAR analysis. J. Volcanol. Geotherm. Res., 213-214: 72-82. https://doi.org/10.1016/j.jvolgeores.2011.11.004

Deformation during 1992 - 2000 [Subsidence; Observed by InSAR]

Start Date: 1992 Stop Date: 2000 Direction: Subsidence Method: InSAR
Magnitude: Unknown Spatial Extent: Unknown Latitude: Unknown Longitude: Unknown

Remarks: InSAR data from the ERS satellite shows an average subsidence rate of 5 cm/year during 1992-2000.

Figure (see Caption)

Interferograms covering the Askja volcano. Their time span is given in the upper right corner. Overlaid are Askja volcanic settings as in Fig. 1. Panels from a to d are interferograms from track 238, panels from e to h are from track 009 and i and l are from track 281 (see Table 1). In panels a and m, we show horizontal GPS displacements.

From: Pagli et al. 2006.


Reference List: Pagli et al. 2006.

Full References:

Pagli, C., Sigmundsson, F., Árnadóttir, T., Einarsson, P., Sturkell, E.,, 2006. Deflation of the Askja volcanic system: contraints on the deformation source from combined inversion of satellite radar interferograms and GPS measurements. J. Volcanol. Geotherm. Res., 152, 97-108.

Deformation during 1983 - 1998 [Subsidence; Observed by GPS, Tilt]

Start Date: 1983 Stop Date: 1998 Direction: Subsidence Method: GPS, Tilt
Magnitude: 75.000 cm Spatial Extent: Unknown Latitude: Unknown Longitude: Unknown

Remarks: Subsidence of 75 centimeters occurred between 1983 and 1998 during a non-eruptive period.


Reference List: Sturkell and Sigmundsson 2000.

Full References:

Sturkell, E. and F. Sigmundsson,, 2000. Continuous deflation of the Askja caldera Iceland, during the 1983-1998 non-eruptive period. J. Geophys. Res., 25671-25684.

Emission History

There is no Emissions History data available for Askja.

Photo Gallery

The dark Vikrahraun lava flow in the foreground was erupted from the NE side of Askja caldera in 1961. The flat-topped mountain in the distance to the NE is Herdubreid, the most famous of Iceland's "table mountains." These steep-sided mountains were formed by repeated eruptions during the Pleistocene through the glacial icecap. The subglacial lava flows and fragmental hyaloclastite rocks ponded against the melted walls of the glacier. Only at the last stage were minor subaerial lavas erupted above the icecap, forming the small summit peak.

Photo by Richie Williams, 1973 (U.S. Geological Survey).
Steam rises in 1967 from a scoria cone along the Vikraborgir crater row, which was formed during an eruption of Askja volcano in 1961. The eruption began on 26 October from a fissure cutting the NE caldera floor. A chain of small scoria cones formed over the eruptive fissure, which fed lava flows that traveled 9.5 km E.

Photo by Richie Williams, 1967 (U.S. Geological Survey).
The steep-walled Viti crater in the foreground was formed during an eruption of Askja that began on January 1, 1875. A powerful plinian phase beginning on March 28 was preceded by caldera collapse that continued slowly for several years. Viti ("Hell") crater, now filled by a small lake, was created by phreatic eruptions that followed the plinian explosions.

Copyrighted photo by Katia and Maurice Krafft, 1974.
Askja's largest historical eruption occurred in 1875. Subsidence of the caldera continued for 40-50 years after the eruption and resulted in the formation of Askja's inner caldera, now filled by Öskjuvatn lake, seen here from the SE. The flat, lava-covered floor of the main caldera can be seen beyond the lake, encircled by the caldera rim.

Photo by Michael Ryan, 1984 (U.S. Geological Survey).
The dark 1921 Batshraun lava flow descends from a vent (left center) on the caldera rim into Öskjuvatn lake across several fault blocks related to caldera subsidence. This aerial view from the northwest shows the small 200-m-wide Viti maar (lower center), which formed during the 1875 eruption. Following slow subsidence of the caldera during and after the 1875 eruption, the depression was filled by the waters of Öskjuvatn lake. During the 1920's, several lava flows erupted from vents surrounding the caldera and flowed into the lake.

Photo by Michael Ryan, 1984 (U.S. Geological Survey).
The dark-colored lava flow at the lower right was erupted during 1961 from a vent on the NE side of Askja caldera and flowed about 9.5 km E. The western rim of the ~8-km-diameter main Askja caldera can be seen in the background, rising above its flat, lava-covered floor. The 1961 vents were on the right in this image. The lake at the upper left is Öskjuvatn, which fills Askja's youngest caldera, formed due to the explosive 1875 eruption. The irregular slopes of the Dyngjufjöll massif in the foreground are formed almost entirely by the products of subglacial eruptions.

Photo by Michael Ryan, 1984 (U.S. Geological Survey).
Askja is a central volcano made up of the Dyngjufjöll massif and at least three calderas, the largest of which is 8 km wide. This view from the SE looks across Öskjuvatn lake within the youngest caldera that formed in 1875 during Askja's largest historical eruption. It truncates a larger caldera, whose wall is seen in the distance above the lava-covered caldera floor. The 100-km-long Askja fissure swarm, which includes the Sveinagjá graben, is also related to the Askja volcanic system.

Photo by Michael Ryan, 1984 (U.S. Geological Survey).
The Askja central volcano, seen here from the north, forms the Dyngjufjöll massif about 20 km N of the Vatnajökull icecap. The massif is mainly composed of subglacial pillow lavas, lava flows, and hyaloclastites, with a broad summit truncated by three overlapping calderas. Much of the Holocene activity has been focused at and around this central massif, but the Askja volcanic system includes fissure swarms extending 170 km N.

Photo by Michael Ryan, 1984 (U.S. Geological Survey).
The 200-m-wide Viti maar crater, filled with a turquoise lake, was formed by phreatic explosions following a major Plinian eruption at Askja on 28-29 March 1875. Note the fault cutting the crater wall on the left. The dark lava flow in the background erupted from a vent on the NE caldera wall in 1921 and entered 4.5-km-wide Öskjuvatn lake, out of view to the right.

Photo by Michael Ryan, 1984 (U.S. Geological Survey).
The dark Batshraun lava flow descending from the left into Öskjuvatn lake was erupted during 1921. The lava flow originated from a vent below the NE rim of Askja's central caldera, and flowed over the low rim of the younger 1875 caldera into the lake. The lava flow was the first of several during the 1920's that flowed into the NE, SE, and W sides of Öskjuvatn lake.

Photo by Michael Ryan, 1984 (U.S. Geological Survey).
Askja, seen here in an aerial view from the south, is a large central volcano truncated by three overlapping calderas. The youngest caldera, formed during the large 1875 eruption, is filled by Öskjuvatn lake (center). This caldera partially truncates the largest Askja caldera, whose floor forms the flat-surfaced area left of the lake now filled with recent lava. The prominent snow-capped peak on the right is Herðubreið, which has not been active in the Holocene.

Photo by Oddur Sigurdsson, 1977 (Icelandic National Energy Authority).
GVP Map Holdings

The maps shown below have been scanned from the GVP map archives and include the volcano on this page. Clicking on the small images will load the full 300 dpi map. Very small-scale maps (such as world maps) are not included. The maps database originated over 30 years ago, but was only recently updated and connected to our main database. We welcome users to tell us if they see incorrect information or other problems with the maps; please use the Contact GVP link at the bottom of the page to send us email.


Title: Midausturland
Publisher: Geodetic Institute, Landmaelingar Islands
Country: Iceland
Year: 1988
Map Type: Topographic
Scale: 1:250,000
Map of Midausturland

Title: Geomorphology of Iceland
Publisher: University of Goteborg, Dept Phys Geog
Country: Iceland
Year: 1984
Map Type: Geology (Geomorphology)
Scale: 1:1,750
Map of Geomorphology of Iceland

Title: Geographical Names of Iceland
Publisher: University of Goteborg, Dept Phys Geog
Country: Iceland
Year: 1984
Map Type: Unknown
Scale: 1:1,750
Map of Geographical Names of Iceland

Title: Fagradalsfjall
Publisher: US Army Map Service
Country: Iceland
Year: 1949
Series: C762
Map Type: Topographic
Scale: 1:50,000
Map of Fagradalsfjall

Title: Herdhubreidhartogl
Publisher: US Army Map Service
Country: Iceland
Year: 1949
Series: C762
Map Type: Topographic
Scale: 1:50,000
Map of Herdhubreidhartogl
Smithsonian Sample Collections Database

The following 2 samples associated with this volcano can be found in the Smithsonian's NMNH Department of Mineral Sciences collections, and may be availble for research (contact the Rock and Ore Collections Manager). Catalog number links will open a window with more information.

Catalog Number Sample Description Lava Source Collection Date
NMNH 111086 Basalt -- --
NMNH 117551-5 Obsidian -- --
External Sites