Satellites monitor the permafrost landforms in Svalbard

Satellites monitor the permafrost landforms in Svalbard

Top image: The PERMASAR team visiting a ground-based installation in Adventdalen just outside Longyearbyen. From left: Professor Hanne Christiansen, project leader Tom Rune Lauknes and Yngvar Larsen. Photo: Hanne Christiansen/UNIS. 

For the first time satellite technology has been incorporated in monitoring of changes in different permafrost landforms. The PERMASAR project can give additional valuable information about the rate of permafrost landform activity in Svalbard.

23 September 2009
Text: Eva Therese Jenssen

For the first time satellites are being directly implemented in the monitoring of the several periglacial landforms in the permafrost landscape in Svalbard.

– It is the first time, as far as we know, that satellite based radar technology is being used to monitor the changes in movement of permafrost landforms, says UNIS professor and TSP Norway project leader Hanne H. Christiansen.

Christiansen, together with senior scientist Yngvar Larsen and project leader Tom Rune Lauknes from the Northern Research Institute, Norut, Tromsø, have had a weekend long project meeting in Longyearbyen to study the satellite images that have been downloaded since June this year, and to visit some of the ground installations measuring movement of the terrain.

The technology used in the project is called InSAR (Interferometric Synthetic Aperture Radar). The project, called PERMASAR, is financed by the Norwegian Space Centre and the oil company StatoilHydro, and Norut is coordinating the project. In addition to UNIS, other scientific partners in the project are the Geological Survey of Norway, the Norwegian Space Centre and the University of Oslo.

Monitor surface changes for kilometers
The permafrost observatory in Svalbard is made up of several ground-based instruments that measure ground thermal conditions but also solifluction (widespread downslope sediment transport in periglacial environments) in some few points in Svalbard; such as in Adventdalen just outside Longyearbyen, and at Kapp Linné at the mouth of Isfjorden.

Satellite image, Kapp Linné, Svalbard

TerraSAR-X satellite images from Kapp Linné: June 12 2009 (left) and July 4 2009 (right). By analyzing these images, among other things evaluate the snow melt, the scientists can calculate changes in the permafrost landforms and compare them to the ground-based instrument data to see if the data correlates. Images: Copyright © 2009 German Aerospace Center (DLR)/Norut.

However, these ground-based instruments only measure the movement at certain points of the terrain surface. The satellite monitoring can give information about the surface changes for several square kilometers.

By comparing the ground-based measurements and the satellite data, the scientists are hoping to get a more comprehensive picture of changes in the upper ground layer over larger parts of the landscape, including several periglacial landforms such as avalanche fans, solifluction sheets, rock glaciers, ice-wedges and pingos.

Norut receives and processes the images from the radar satellites TerraSAR-X and Radarsat-2 that produce images of the study areas in Svalbard with an interval of 11 and 24 days, respectively.

The project has two different agendas; in addition to monitoring the movement of permafrost landforms, the scientists also can assess the snow cover and the snow melt during the season, according to Lauknes.

– It is a quite unique project because it is the first time we employ satellite images to monitor the changes in the permafrost terrain over a whole season – from the snow starts melting in June until October, when the ground is frozen again in Svalbard, Lauknes says.

After the season ends in October the team will gather all the data, process the images to see if the two different measuring techniques match, and if so in the future can give a better insight into the movement of several permafrost landforms.

– We hope to be able to present the results from this project at the Third European Permafrost Conference here at UNIS in June next year, Christiansen says.

So far the project has only been funded for one season, but the team hopes to get funding for the 2010 summer season too, in order to include also better understanding of the annual changes, and not only seasonal summer changes in the Svalbard landscape.

The PERMASAR project also includes monitoring of the Nordnes unstable mountain area in Troms, where also a part of the TSP Norway project is investigating the permafrost distribution.

Satellite image, Kapp Linné, Svalbard 2009.

TerraSAR-X satellite image from Kapp Linné September 12 2009. Image: Copyright © 2009 German Aerospace Center (DLR)/Norut.

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