Annual variations of frost table in Kangerlussuaq Airport, western Greenland

Ground-penetrating radar (GPR) has been used to study the annual variations of the frost table beneath the southern parking area at Kangerlussuaq Airport, western Greenland. In autumn 2000, three test areas were painted white in order to reduce further development of depressions in the asphalt pavement initiated by permafrost degradation. One of these white painted areas has been used in the investigations to compare the annual variations of the frost table underneath a normal black asphalt surface to with that below a more reflective surface. The investigations were carried out from July 2005 until August 2006. The GPR measurements have shown a clear correlation between the use of the reflective surface and a reduced depth in the annual variations to the frost table. In late summer (August) the difference in the depths to the frost table is almost 20 ns, which corresponds to approximately 0.9 m. This constitutes a major difference in the thermal conditions below the reflective surface and the normal black asphalt surface.