Last updated 27 February 2024

An important aspect of climate change in the Arctic is melting of the permafrost. In Svalbard, monitoring of permafrost is ongoing in several boreholes, including at Janssonhaugen, 20 km from Longyearbyen. Heating and thawing of permafrost may result in changes in landscape and greater instability in hillsides, increasing the probability of landslides and avalanches. Thawing permafrost can damage buildings and infrastructure and cultural heritage sites in coastal areas are exposed to increased erosion.

Weather station at Janssonhaugen. Photo: Ketil Isaksen / The Norwegian Meteorological Institute.

What is being monitored?


At suitable places, temperature measurements in boreholes in permafrost give firm indications of changes in climate. Data from Janssonhaugen show a distinct rise in temperature right down to 40 metres. Temperature variations at the ground surface through the year will be both delayed and moderated downwards. At a depth of 15–20 metres, temperature variations through the year are balanced out. Changes in the average temperature at the ground surface over several years and decades will be transmitted to greater depths as temperature waves. These measurements are therefore a valuable supplement to more traditional climate data from meteorological stations in Svalbard.
(Cite these data: Norwegian Meteorological Institute (2024). Ground temperature in permafrost, Janssonhaugen. Environmental monitoring of Svalbard and Jan Mayen (MOSJ). URL:

The uppermost soil layer in the ground overlying the permafrost thaws each summer. This is called the active layer. In general, the active layer has become thicker since 1998, so that the surface of the permafrost now in average lies about  30 cm deeper than it did around the turn of the century. In the longer term, this thawing can create stability problems at the surface. Parts of the spring and summer of 2021 were cooler compared to recent years and contributed so that the thickness of the active layer this summer was quite similar to the first years of the series from Janssonhaugen. The greatest depth to date was recorded after the record warm summer of 2023.
(Cite these data: Norwegian Meteorological Institute (2024). Thickness of active layer in permafrost, Janssonhaugen. Environmental monitoring of Svalbard and Jan Mayen (MOSJ). URL:

Details on these data

Last updated27 February 2024
Update intervalYearly
Next updateMarch 2025
Executive organizationNorwegian Meteorological Institute
Contact personsKetil Isaksen


Thermistors attached to a data logger record temperatures in the borehole. The logger is programmed to observe the temperature four times a day. The data are filtered (gliding average over 366 days) to remove small (± 0.02°C) temperature variations caused by seasonal systematic noise in the automatic data collection.

The absolute precision is ± 0.05°C and the relative precision is ± 0.02°C.


The measurement programme was set up in accordance with guidelines determined by the leading experts in Europe on permafrost monitoring and exceeds the international requirements for precision.

Other metadata

See the Global Terrestrial Network for Permafrost

Status and trend

Permafrost monitoring began in 1998. Analyses show that the temperature at 10 meters depth in the permafrost is rising on average 0.8°C per decade.  At a depth of 40 metres, the rise in temperature has been accelerating over the past 25 years.

 During the monitoring period, it has been recorded increased temperatures down to a depth of 100 m in the permafrost at Janssonhaugen. The active layer has on average become approximately 30 cm thicker since 1998.

At international level, considerable research is linked to studies of permafrost which contains large quantities of organic carbon and which could be broken down and release the greenhouse gases carbon dioxide (CO2) and methane (CH4) when ground temperatures rise and the permafrost thaws. Increases in the quantities of CO2 and CH4 are the principal contributors to global warming. Further warming and thawing of the permafrost could contribute to an even greater increase in these two greenhouse gases.

Causal factors

The warming of the permafrost at Janssonhaugen is first and foremost a response to the rise in the air temperature in recent decades.

Studies so far show that any changes in the snow cover have had no major effect on the permafrost at Janssonhaugen. This is because the locality is extremely exposed to wind, and the ground around the borehole is blown free of snow for large parts of the winter.


All buildings in the Svalbard settlements are built on piles driven into the permafrost, and roads, bridges, airports and other infrastructure are also constructed on permafrost. When warming and thawing of the permafrost occurs, the infrastructure may be affected in the longer term. In addition, the permafrost is essential for stabilizing steep mountainsides, which may become more unstable when warming takes place. This will have consequences for travelling, and also potentially for animal life if, for example, areas with arctic fox dens become unstable and collapse.

Many cultural heritage remains in Svalbard are situated in the shore zone, where they may be vulnerable to increasing erosion in the future and sediment damage as a result of thawing of the permafrost.

On a circumpolar level, the most important consequence of the warming and thawing of the permafrost is, nevertheless, that large volumes of greenhouse gases, like CO2 (carbon dioxide) and CH(methane), may be released if ever deeper layers of the permafrost thaw. These gases have been kept out of the atmosphere because the organic carbon has been frozen in the ground. The release of such greenhouse gases may lead to a further rise in the temperature and thawing of the permafrost. This is one of the many feedback mechanisms in the Arctic, and attempts are continually being made to improve the estimates of the emissions from thawing permafrost.

About the monitoring

In cold permafrost, like in Svalbard, there is usually insignificant or no circulation of groundwater to disturb the progress of the temperature in the ground. By observing changes in temperature of a depth of 20–40 metres or more within a few years,  it is possible to calculate the changes in temperature that have taken place near the ground surface over the last decades.

It transpires that the active layer, which is the uppermost part of the permafrost that thaws each summer, is becoming thicker over time. This is directly connected with warmer summers and brings with it problems like increased risk of landslides, more erosion on the coast and changes in the landscape. In recent years, international climate researchers have therefore become increasingly interested in the monitoring of permafrost.

Places and areas

Further reading



  1. Christiansen, H. H., Etzelmüller, B., Isaksen, K., Juliussen, H., Farbrot, H., Humlum, O., … & Ødegård, R. S. (2010). The thermal state of permafrost in the nordic area during the international polar year 2007–2009. Permafrost and Periglacial Processes21(2), 156-181.
  2. Etzelmüller, B., Guglielmin, M., Hauck, C., Hilbich, C., Hoelzle, M., Isaksen, K., … & Ramos, M. (2020). Twenty years of European mountain permafrost dynamics—the PACE legacy. Environmental Research Letters15(10), 104070.
  3. Haeberli, W., Noetzli, J., Arenson, L., Delaloye, R., Gärtner-Roer, I., Gruber, S., … & Phillips, M. (2010). Mountain permafrost: development and challenges of a young research field. Journal of glaciology56(200), 1043-1058.
  4. Hansen, B. B., Isaksen, K., Benestad, R. E., Kohler, J., Pedersen, Å. Ø., Loe, L. E., … & Varpe, Ø. (2014). Warmer and wetter winters: characteristics and implications of an extreme weather event in the High Arctic. Environmental Research Letters9(11), 114021.
  5. Isaksen, K., Sollid, J. L., Holmlund, P., & Harris, C. (2007). Recent warming of mountain permafrost in Svalbard and Scandinavia. Journal of Geophysical Research: Earth Surface112(F2).
  6. Isaksen, K., Benestad, R. E., Harris, C., & Sollid, J. L. (2007). Recent extreme near‐surface permafrost temperatures on Svalbard in relation to future climate scenarios. Geophysical Research Letters34(17).
  7. Isaksen, K., Lutz, J., Sørensen, A. M., Godøy, Ø., Ferrighi, L., Eastwood, S., & Aaboe, S. (2022). Advances in operational permafrost monitoring on Svalbard and in Norway. Environmental Research Letters17(9), 095012.
  8. Smith, S. L., O’Neill, H. B., Isaksen, K., Noetzli, J., & Romanovsky, V. E. (2022). The changing thermal state of permafrost. Nature Reviews Earth & Environment3(1), 10-23.
  9. Smith, S.L., Romanovsky, V.E., Isaksen, K., Nyland, K.E., Kholodov, A.L., Shiklomanov, N.I., Streletskiy, D.A., Drozdov, D.S., Malkova, G.V., & Christiansen, H.H. (2022). Permafrost [in “State of the Climate in 2021”]. Bull. Amer. Meteor. Soc., 103 (8), S286–S290.