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  • Station or cluster: CryoNet Station
  • Type: Reference
  • Attribute(s):
  • Belongs to cluster: Hofsj√∂kull
  • WMO ID (if any):
  • Shape: polygon
  • Latitude, longitude: 64.8090, -18.8693
  • Altitude and/or range (m): 1790; 600-1800
  • Landscape: Icecap
  • Year established: 1988
  • Year-round? No
  • Operations contact: Thorsteinn Thorsteinsson
  • Science contact: Thorsteinn Thorsteinsson
  • Data contact: Thorsteinn Thorsteinsson
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Hofsjökull Ice Cap
Reference CryoNet Station Information

The Hofsjökull Ice Cap is a key area within the North Atlantic region for investigating the effects of climate variations on glacier mass balance. Glacier changes in Iceland are relatively well known within the timespan of instrumental meteorological observations and mass balance measurements have been conducted on Hofsjökull since 1988. The data provide constraints for modelling the changes of one of Iceland´s large highland ice caps to projected atmospheric warming in the period 2000–2200. Such modeling is important for hydropower utilisation and general assessment of changes in the natural environment of Iceland resulting from global warming.

Other Networks to Which This CryoNet Station Belongs

Measurement Methods Used

Other relevant measurement method documents:

Östrem G. and M. Brugmann, 1991, Glacier Mass Balance Measurements. A manual for field and office work. National Hydrology Research Institute (Canada), Science Report No. 4, 224 pp.

Data Information


Björnsson H, Pálsson F, Gudmundsson S, Magnússon E, Aðalgeirsdóttir G, Jóhannesson T, Berthier E, Sigurdsson O, Thorsteinsson Th: Contribution of Icelandic ice caps to sea level rise: Trends and variability since the Little Ice Age. Geophys. Res. Lett. 2013, 40 (8), 1546-1550. DOI: 10.1002/grl.50278

Einarsson, B. & Jónsson, S. (2010). The effect of climate change on runoff from two watersheds in Iceland. Icelandic Meteorological Office, Report, VÍ 2010-016. 34 pp.

Jóhannesson, T., G. Aðalgeirsdóttir, H. Björnsson, P. Crochet, E.B. Elíasson, S. Guðmundsson, J.F. Jónsdóttir, H. Ólafsson, F. Pálsson, Ó. Rögnvaldsson, O. Sigurðsson, Á. Snorrason, Ó. G. B. Sveinsson & Th. Thorsteinsson (2007). Effect of climate change on hydrology and hydro-resources in Iceland. Final Report of the project Veður og orka (Climate and Energy), OS-2007/011. 91 pp.

Jóhannesson T, Björnsson H, Magnússon E, Guðmundsson S, Pálsson F, Sigurðsson O, Thorsteinsson Th, Berthier E: Ice-volume changes, bias estimation of mass-balance measurements and changes in subglacial lakes derived by lidar-mapping of the surface of Icelandic glaciers. Annals of Glaciology 2013, 54 (63), 63-74. doi: 10.3189/2013AoG63A422

Sigurðsson, O., T. Jóhannesson, Th. Thorsteinsson & G. Larsen (2002). Ice core drilling on the Hofsjökull ice cap for measuring glacier mass balance. Nordic Hydrological Programme Report, 47. Proceedings of the XXII Nordic Hydrological Conference, Røros, Norway, August 4-7 2002.

Thorsteinsson Th, Björnsson H (Eds): Climate Change and Energy Systems. Impacts, Risks and Adaptation in the Nordic and Baltic Countries. Nordic Council of Ministers, TemaNord 2011:502, 228 pp.

Thorsteinsson, Th., T. Jóhannesson, O. Sigurðsson, E.Ö. Hreinsson, S.M. Ágústsson & E. Tómasson (2003). Afkomumælingar á hábungu Hofsjökuls í maí 2003 (Mass balance measurements at the summit of Hofsjökull, May 2003). National Energy Authority, Report OS/2003-53. 51 pp.


The measurements made at Hofsjökull Ice Cap are listed in the following tables. (Note: If End Year is blank, measurements are ongoing.)

Cryosphere Measurements

Element Variable Start Year End Year Frequency
SnowSnow on the ground (WMO code 0957)1988Continuous
SnowSnow water equivalent1988Continuous
SnowSnowpack profile1988Continuous
GlacierAnnual mass balance1988Continuous
GlacierWinter mass balance1988Continuous
GlacierGlacial runoff1948Continuous
GlacierSurface topography1983Sporadic
GlacierFacies, snowline1988

Atmosphere Measurements

Element Variable Start Year End Year Frequency
MetAir temperature2016Continuous
MetHumidity/vapour pressure2016Continuous
MetWind speed and direction2016Continuous
MetAir pressure2016
RadiationDownwelling shortwave2016Continuous
RadiationUpwelling shortwave2016Continuous

Measurement Notes and Other Measurements

Category Description or List
SnowSnow measurements at the Hveravellir CryoNet Station were started in 1965.

Snow measurements at the Hofjökull CryoNet Station were started in 1988, forming part of the mass balance program on the ice cap.

GlacierVariations of the ice cap front have been monitored regularly at the following outlet glaciers from Hofsjökull:

Múlajökull: Since 1932

Nauthagajökull: Since 1932

Blágnípujökull: Since 1932

Sátujökull: Since 1950

Kvíslajökull: Since 2002

Sporadic observations exist from other outlets.

HydrologyHydrometric observations are conducted on glacial rivers flowing from Hofsjökull to S- and N-Iceland. The longest data series, on the river Þjórsá, goes back to 1948. At present 10 hydrometric stations on rivers flowing from Hofsjökull (of which 3 are included on the accompanying map) deliver real-time data on discharge, water temperature and electric conductivity. Samples for measurements of suspended sediment load are regularly collected. These hydrological measurements, showing diurnal and seasonal variations and glacier floods, provide a unique opportunity for glacier hydrology research.
EcologySouth of the ice cap lies the Þjórsárver natural reserve, a unique ecosystem protected by the international RAMSAR convention on wetlands and one of the few regions in Iceland where permafrost mounds have been observed and studied in detail. Detailed studies of tundra ecosystems have been carried out in Þjórsárver. In addition, communities of microbial and invertebrate life in glacial rivers of the Hofsjökull region have been investigated.
OceanographyNo oceanographic observations are applicable.
OtherSeveral stations for continuous, high-precision GPS-monitoring of crustal movements are operated in Iceland. It is proposed to include seven stations operated within the ranks of the CHIL (Central Highland) network in the Hofsjökull Cryonet site. These stations have been in operation since 2007 and together they yield information on isostatic adjustment in response to mass balance changes of Hofsjökull and other ice caps in the Icelandic highland.

The forefield of Múlajökull, a surge-type outlet glacier from Hofsjökull, has attracted the attention of geomorphologists in recent years, as the only known presently active drumlin field on Earth.

Last updated: 31 May 2017