Dynamics of permafrost submitted to a warning climate

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Permafrost covers about 45% of Canada and therefore Northern landscape evolution is highly dependent on the dynamics of permafrost aggradation and degradation through time. Climatic changes play a key role in the dynamics of permafrost. Changing temperature, precipitation and sedimentary regimes affect the thermal state and the mechanics of permafrost. On the long term, the projected climate warming scenarios for Northern Canada suggest that the permafrost will be markedly affected. These changes will have a profound impact on northern ecosystems via changes in the physical environment and the hydrological cycle. Where the ground is ice-rich the adjustment of the permafrost to climatic conditions will induce thermokarst and thermo-erosion processes related to erosion, ground ice melting, thaw-settlement and mass movement of the surface. These natural processes will be further exacerbated by human activities. In the recent decades, Northern permafrost regions of Canada have experienced a sustained growth and are expected to undergo a tremendous development in the near future. Population growth, as well as oil, gas and mining exploration require the construction of additional roads, railways, airstrips and pipelines which create heavy pressures on the environment. The construction of infrastructures inevitably affects the thermal regime of the underlying permafrost through disturbance of the surface. Recurrent maintenance operations, rehabilitation, reconstruction and relocalization of damaged infrastructures will become very costly. This general objective of this research program is to answer pressing questions of permafrost degradation in natural settings and applied to transport infratsructures. This research program proposes to adopt a field-based geomorphological approach to study the fundamentals of permafrost degradation processes on various time scales (year to decades) and to develop engineering techniques to prevent permafrost degradation and to rehabilitate (re-freeze) thawed permafrost. This research program will help Canadian communities, governments and the industry to develop science-based adaptation strategies to cope with warming and changing permafrost environments.