TARAJULIK - Salinity effects on heat transfer in permafrost soils and the impact on stability of critical infrastructure in Greenland

Tarajulik (means "containing salt" in West Greenlandic language) works on establishing a better understanding of the impacts of climate warming on thermal and mechanical stability of saline permafrost. Saline permafrost is a ground material permanently below 0°C containing dissolved salts (salinity) in the unfrozen pore liquid. The salinity lowers the freezing point and saline permafrost can thus have strength and deformation properties of thawed ground, even at negative temperatures. It is a terrain particularly sensitive to temperature disturbances and a major geohazard.

Within Tarajulik, we conduct standard and advanced permafrost soil classification of natural samples from four permafrost-affected communities in West Greenland: Sisimiut, Kangerlussuaq, Ilulissat and Qaanaaq. The results of the classification will be published in a freely accessible web-based database for the benefit of engineers and stakeholders in Greenland, and scientists worldwide.

With further climate warming, the compromised mechanical strength of warming saline permafrost will have a significant impact on stability of infrastructure built on it. Ground thermal models can help forecasting the thermal degradation, when properly calibrated. Therefore within Tarajulik, we also collect experimental data for parameterization of a model of heat transfer in frozen soils of various salinities. The improved thermal model is expected to lead to more reliable ground stability predictions.

The main outcomes of Tarajulik will be:

1) Improved prediction capacity for thermal and mechanical stability of saline permafrost;
2) Development of the experimental setup for advanced thaw strain measurements;
3) Database of consistently-measured geotechnical properties and thaw consolidation potential for typical Greenlandic soils