1. Geological aspests of traffic engineering - a case study 5. Villumsen, A. et al. 2007: Road Construction in Greenland - The Greenlandic case. – Arctic Technology Center, p. 85. Engineering and Environmental Geology

2. The Sisimiut-Kangerlussuaq road Road-building projects in the Arctic are very different from projects to be carried out in Denmark. The presence of permafrost below the surface means the material used for construction must be chosen carefully, and that the effects of variations in temperature in the uppermost layers can give rise to problems. The fact that the areas are usually very thinly populated also means that road construction must be achieved using the existing infrastructure. It is necessary to transport road-building material along the road that is under construction. This means that the process is expensive and time consuming

3. 1. Geological and geographical overview The area between Sisimiut and Kangerlussuaq belongs geologically to the “Nagssugtoquidian Mobile Belt” which here consists dominantly of banded gneisses. The gneisses have been extensively metamorphosed and were probably originally granites. The gneisses are commonly weathered and fractured. The area has been divided into two structural complexes, the Isotoq gneisses in the north and the Ikertoq gneisses in the south. These two complexes are separated by a fault zone which crosses the road route. The gneissic rocks here are of poor quality which must be taken in to consideration during construction of the road. During the Quaternary the area was strongly eroded by glaciers which scoured out deep valleys. The Ikertoq complex was particularly susceptible the effects of ice and climatic variations, as is evident from its topographic expression.

4. 2. Suitable materials for road construction and permafrost Subsurface frost occurs, per definition, when the temperature falls below 0°C. Permafrost, however, requires that the temperature remains below 0°C for two successive years. A rule of thumb is that the average surface temperature has to be below -3°C for permafrost to develop. The geographical extent of permafrost is divided into three categories: areas with continuous, discontinuous or sporadic permafrost. In areas with continuous permafrost, unfrozen areas only occur in connection with streams/rivers and large lakes where the water prevents freezing. At Sisimiut and Kangerlussuaq the average annual temperature is -3.9 and -5.7°C respectively, which places them respectively in the discontinuous and continuous zones.

5. 3. Geological model for the area The ~170 km long stretch between Kangerlussuaq and Sisimiut has been divided into 7 areas starting from Sisimiut. The areas are as follows: 1: Sisimiut, 2: Første Fjorden, 3: Uttoqqaat, 4: Itinneq, 5: Amitsorssuaq, 6: Taserssuaq and 7: Kangerlussuaq. Students from The Technical University of Denmark and Aarhus University have collected geophysical data in the form of geoelectric profiles and probes together with seismic, georadar and measurements with the stangslingram, as well as drilling boreholes, photography and collecting soil samples along the entire stretch. The following is based on the reports produced by these students.

6. 4. Environmental and conservation aspects Construction of a road from Sisimiut to Kangerlussuaq is an ambitious project that will help promote tourism, trade and industry and will improve the global infrastructure in Greenland by provision of a well-organised transport system. From an environmental point of view, the most negative influence will take place during the construction phase in the form of noise, dust, vibrations and the disturbance of fauna and flora. Most of these disturbances will be temporary, but some will have a permanent effect, such as changes to the landscape. The operative phase after completion of the road will have less influence because of the relatively small volume of traffic. The main problem will be water pollution. It will be necessary to carry out further studies of the pollution risks before construction commences, but preliminary data suggest that it will be possible to carry out the road-building project without causing serious environmental damage.

7. Thank you for your attention!