RECENT CLIMATIC TREND AND THERMAL RESPONSE OF PERMAFROST IN SALLUIT, NORTHERN QUEBEC, CANADA

Not all places may in fact warm under global change scenarios. This pa per presents an example of climatic cooling from northern Quebec, Cana da. Ground temperature measurements along the southern shore of Hudson Strait, northern Quebec indicate a cooling trend over the last seven years (1987-93). Long-term air temperature records show that this area has actually experienced continuous cooling for more than 40 years. R elated studies suggest that the cooling is likely to continue due to f reshening of subpolar water in the North Atlantic and Labrador Sea are a. A one-dimensional geothermal model was used to simulate the effect of continued cooling on permafrost thermal regime in Salluit, northern Quebec. The results show that, if the climatic trend continues for th e next 50 years, the thickness of the active layer would decrease by 3 0 cm (from 2.3 to 2.0 m) in gneiss and by 20 cm (from 1.3 to 1.1 m) in till. Permafrost temperature at 20 m depth would decrease by 0.65 deg rees C. Under the cooling scenario, rate of permafrost creep and slope activities would be reduced. Ice-wedge regrowth would continue, and t he buried ice wedges may even become reactivated. The results also ind icate that regional snow precipitation data cannot be used directly in predicting ground thermal regimes.